Is there any documentation as to how the three AT90USB1286 builds differ?  I've tried my layout (18x8 matrix, config below if it's helpful) on an empty Teensy 2.0++ using the Fullsize 16mhz and Jumbo and don't get any output using a wire between pins.  I'm sure someone said they got a key to output...
# Easy AVR USB Keyboard Firmware Keymapper
# Copyright (C) 2013-2016 David Howland
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program.  If not, see <http://www.gnu.org/licenses/>.
import easykeymap.templates.AT90USB1286_16MHz_FULLSIZE as firmware
from easykeymap.ioports import *
from easykeymap.helper import make_matrix_config
description = "Ducky Zero"
unique_id = "DUCKY_001"
cfg_name = "Ducky 108"
teensy = True
hw_boot_key = False
display_height = int(6.5*4)
display_width = int(22.5*4)
num_rows = 8
num_cols = 18
strobe_cols = True
strobe_low = True
matrix_hardware, matrix_strobe, matrix_sense = make_matrix_config(
    strobe_cols=strobe_cols,
    strobe_low=strobe_low,
    rows=[D2, D1, D4, B0, D0, C5, B7, F0],
    cols=[F7, F4, B2, B3, B4, B5, E6, B6, F2, F3, F5, D5, D6, C7, C6, E0, F6, E1],
    device=firmware.device
)
num_leds = 2
num_ind = 2
num_bl_enab = 2
led_definition = [
    ('Caps Key', 'Caps Lock'),
    ('Num Key', 'Num Lock')
]
led_hardware = [
    ( REF_PORTD, 6, LED_DRIVER_PULLUP ),
    ( REF_PORTF, 1, LED_DRIVER_PULLUP )
]
backlighting = False
bl_modes = [
    ( 0, 0 ),
    ( 1, 1 )
]
KMAC_key = None
keyboard_definition = [
    [((4, 4), (3, 2), 'HID_KEYBOARD_SC_ESCAPE'),
     (4, None, '0'),
     ((4, 4), (1, 3), 'HID_KEYBOARD_SC_F1'),
     ((4, 4), (1, 4), 'HID_KEYBOARD_SC_F2'),
     ((4, 4), (6, 4), 'HID_KEYBOARD_SC_F3'),
     ((4, 4), (4, 4), 'HID_KEYBOARD_SC_F4'),
     (2, None, '0'),
     ((4, 4), (0, 10), 'HID_KEYBOARD_SC_F5'),
     ((4, 4), (4, 8), 'HID_KEYBOARD_SC_F6'),
     ((4, 4), (6, 8), 'HID_KEYBOARD_SC_F7'),
     ((4, 4), (1, 8), 'HID_KEYBOARD_SC_F8'),
     (2, None, '0'),
     ((4, 4), (1, 12), 'HID_KEYBOARD_SC_F9'),
     ((4, 4), (0, 12), 'HID_KEYBOARD_SC_F10'),
     ((4, 4), (4, 12), 'HID_KEYBOARD_SC_F11'),
     ((4, 4), (0, 14), 'HID_KEYBOARD_SC_F12'),
     (1, None, '0'),
     ((4, 4), (0, 11), 'HID_KEYBOARD_SC_PRINT_SCREEN'),
     ((4, 4), (7, 11), 'HID_KEYBOARD_SC_SCROLL_LOCK'),
     ((4, 4), (7, 10), 'HID_KEYBOARD_SC_PAUSE'),
     (1, None, '0'),
     ((4, 4), (1, 12), 'SCANCODE_MUTE'),
     ((4, 4), (0, 12), 'SCANCODE_VOL_DEC'),
     ((4, 4), (4, 12), 'SCANCODE_VOL_DEC'),
     ((4, 4), (2, 12), 'SCANCODE_CALC')],
    2,
    [((4, 4), (1, 2), 'HID_KEYBOARD_SC_GRAVE_ACCENT_AND_TILDE'),
     ((4, 4), (0, 2), 'HID_KEYBOARD_SC_1_AND_EXCLAMATION'),
     ((4, 4), (0, 3), 'HID_KEYBOARD_SC_2_AND_AT'),
     ((4, 4), (0, 4), 'HID_KEYBOARD_SC_3_AND_HASHMARK'),
     ((4, 4), (0, 5), 'HID_KEYBOARD_SC_4_AND_DOLLAR'),
     ((4, 4), (1, 5), 'HID_KEYBOARD_SC_5_AND_PERCENTAGE'),
     ((4, 4), (1, 6), 'HID_KEYBOARD_SC_6_AND_CARET'),
     ((4, 4), (0, 6), 'HID_KEYBOARD_SC_7_AND_AND_AMPERSAND'),
     ((4, 4), (0, 7), 'HID_KEYBOARD_SC_8_AND_ASTERISK'),
     ((4, 4), (0, 8), 'HID_KEYBOARD_SC_9_AND_OPENING_PARENTHESIS'),
     ((4, 4), (0, 9), 'HID_KEYBOARD_SC_0_AND_CLOSING_PARENTHESIS'),
     ((4, 4), (1, 9), 'HID_KEYBOARD_SC_MINUS_AND_UNDERSCORE'),
     ((4, 4), (1, 7), 'HID_KEYBOARD_SC_EQUAL_AND_PLUS'),
     ((8, 4), (7, 10), 'HID_KEYBOARD_SC_BACKSPACE'),
     (1, None, '0'),
     ((4, 4), (1, 14), 'HID_KEYBOARD_SC_INSERT'),
     ((4, 4), (1, 16), 'HID_KEYBOARD_SC_HOME'),
     ((4, 4), (1, 15), 'HID_KEYBOARD_SC_PAGE_UP'),
     (1, None, '0'),
     ((4, 4), (3, 13), 'HID_KEYBOARD_SC_NUM_LOCK'),
     ((4, 4), (3, 14), 'HID_KEYBOARD_SC_KEYPAD_SLASH'),
     ((4, 4), (3, 15), 'HID_KEYBOARD_SC_KEYPAD_ASTERISK'),
     ((4, 4), (2, 15), 'HID_KEYBOARD_SC_KEYPAD_MINUS')],
    [((6, 4), (6, 2), 'HID_KEYBOARD_SC_TAB'),
     ((4, 4), (7, 2), 'HID_KEYBOARD_SC_Q'),
     ((4, 4), (7, 3), 'HID_KEYBOARD_SC_W'),
     ((4, 4), (7, 4), 'HID_KEYBOARD_SC_E'),
     ((4, 4), (7, 5), 'HID_KEYBOARD_SC_R'),
     ((4, 4), (6, 5), 'HID_KEYBOARD_SC_T'),
     ((4, 4), (6, 6), 'HID_KEYBOARD_SC_Y'),
     ((4, 4), (7, 6), 'HID_KEYBOARD_SC_U'),
     ((4, 4), (7, 7), 'HID_KEYBOARD_SC_I'),
     ((4, 4), (7, 8), 'HID_KEYBOARD_SC_O'),
     ((4, 4), (7, 9), 'HID_KEYBOARD_SC_P'),
     ((4, 4), (6, 7), 'HID_KEYBOARD_SC_OPENING_BRACKET_AND_OPENING_BRACE'),
     ((4, 4), (6, 9), 'HID_KEYBOARD_SC_CLOSING_BRACKET_AND_CLOSING_BRACE'),
     (1, None, '0'),
     ((5, 8), (3, 12), 'HID_KEYBOARD_SC_ENTER'),
     (1, None, '0'),
     ((4, 4), (1, 13), 'HID_KEYBOARD_SC_DELETE'),
     ((4, 4), (0, 16), 'HID_KEYBOARD_SC_END'),
     ((4, 4), (0, 15), 'HID_KEYBOARD_SC_PAGE_DOWN'),
     (1, None, '0'),
     ((4, 4), (7, 13), 'HID_KEYBOARD_SC_KEYPAD_7_AND_HOME'),
     ((4, 4), (7, 14), 'HID_KEYBOARD_SC_KEYPAD_8_AND_UP_ARROW'),
     ((4, 4), (7, 15), 'HID_KEYBOARD_SC_KEYPAD_9_AND_PAGE_UP'),
     ((4, 8), (7, 16), 'HID_KEYBOARD_SC_KEYPAD_PLUS')],
    [((7, 4), (6, 3), 'HID_KEYBOARD_SC_CAPS_LOCK'),
     ((4, 4), (5, 2), 'HID_KEYBOARD_SC_A'),
     ((4, 4), (5, 3), 'HID_KEYBOARD_SC_S'),
     ((4, 4), (5, 4), 'HID_KEYBOARD_SC_D'),
     ((4, 4), (5, 5), 'HID_KEYBOARD_SC_F'),
     ((4, 4), (4, 5), 'HID_KEYBOARD_SC_G'),
     ((4, 4), (4, 6), 'HID_KEYBOARD_SC_H'),
     ((4, 4), (5, 6), 'HID_KEYBOARD_SC_J'),
     ((4, 4), (5, 7), 'HID_KEYBOARD_SC_K'),
     ((4, 4), (5, 8), 'HID_KEYBOARD_SC_L'),
     ((4, 4), (5, 9), 'HID_KEYBOARD_SC_SEMICOLON_AND_COLON'),
     ((4, 4), (4, 9), 'HID_KEYBOARD_SC_APOSTROPHE_AND_QUOTE'),
     ((4, 4), (5, 11), 'HID_KEYBOARD_SC_NON_US_HASHMARK_AND_TILDE'),
     (-19, None, '0'),
     ((4, 4), (6, 13), 'HID_KEYBOARD_SC_KEYPAD_4_AND_LEFT_ARROW'),
     ((4, 4), (6, 14), 'HID_KEYBOARD_SC_KEYPAD_5'),
     ((4, 4), (6, 15), 'HID_KEYBOARD_SC_KEYPAD_6_AND_RIGHT_ARROW'),
     (-4, None, '0')],
    [((5, 4), (6, 1), 'HID_KEYBOARD_SC_LEFT_SHIFT'),
     ((4, 4), (2, 2), 'HID_KEYBOARD_SC_NON_US_BACKSLASH_AND_PIPE'),
     ((4, 4), (3, 2), 'HID_KEYBOARD_SC_Z'),
     ((4, 4), (3, 3), 'HID_KEYBOARD_SC_X'),
     ((4, 4), (3, 4), 'HID_KEYBOARD_SC_C'),
     ((4, 4), (3, 5), 'HID_KEYBOARD_SC_V'),
     ((4, 4), (2, 5), 'HID_KEYBOARD_SC_B'),
     ((4, 4), (2, 6), 'HID_KEYBOARD_SC_N'),
     ((4, 4), (3, 6), 'HID_KEYBOARD_SC_M'),
     ((4, 4), (3, 7), 'HID_KEYBOARD_SC_COMMA_AND_LESS_THAN_SIGN'),
     ((4, 4), (3, 8), 'HID_KEYBOARD_SC_DOT_AND_GREATER_THAN_SIGN'),
     ((4, 4), (2, 9), 'HID_KEYBOARD_SC_SLASH_AND_QUESTION_MARK'),
     ((11, 4), (5, 1), 'HID_KEYBOARD_SC_RIGHT_SHIFT'),
     (5, None, '0'),
     ((4, 4), (4, 16), 'HID_KEYBOARD_SC_UP_ARROW'),
     (5, None, '0'),
     ((4, 4), (5, 13), 'HID_KEYBOARD_SC_KEYPAD_1_AND_END'),
     ((4, 4), (5, 14), 'HID_KEYBOARD_SC_KEYPAD_2_AND_DOWN_ARROW'),
     ((4, 4), (5, 15), 'HID_KEYBOARD_SC_KEYPAD_3_AND_PAGE_DOWN'),
     ((4, 8), (5, 16), 'HID_KEYBOARD_SC_KEYPAD_ENTER')],
    [((5, 4), (1, 10), 'HID_KEYBOARD_SC_LEFT_CONTROL'),
     ((5, 4), (6, 0), 'HID_KEYBOARD_SC_LEFT_GUI'),
     ((5, 4), (4, 11), 'HID_KEYBOARD_SC_LEFT_ALT'),
     ((25, 4), (4, 13), 'HID_KEYBOARD_SC_SPACE'),
     ((5, 4), (2, 11), 'HID_KEYBOARD_SC_RIGHT_ALT'),
     ((5, 4), (7, 0), 'HID_KEYBOARD_SC_RIGHT_GUI'),
     ((5, 4), (2, 8), 'HID_KEYBOARD_SC_APPLICATION'),
     ((5, 4), (3, 10), 'HID_KEYBOARD_SC_RIGHT_CONTROL'),
     (1, None, '0'),
     ((4, 4), (2, 16), 'HID_KEYBOARD_SC_LEFT_ARROW'),
     ((4, 4), (2, 13), 'HID_KEYBOARD_SC_DOWN_ARROW'),
     ((4, 4), (2, 14), 'HID_KEYBOARD_SC_RIGHT_ARROW'),
     (1, None, '0'),
     ((8, 4), (4, 14), 'HID_KEYBOARD_SC_KEYPAD_0_AND_INSERT'),
     ((4, 4), (4, 15), 'HID_KEYBOARD_SC_KEYPAD_DOT_AND_DELETE'),
     (-4, None, '0')]
]
alt_layouts = {}