So I've decided to go into deep waters and try to create my own keyboard without having any experience in coding at all

My plan is so far:
Tenkeyless keyboard with programmable leds on each key.
So what i want to do is run the Teensy 3.1 for this, dunno if that is smart or has been done at all (not alot about it on the web)
The plan is to do all this with the combination of a 8ch Mux and PWM. I know that the maximum output of the teensy is 3.3V 100mA on all ports, this ofc limits the possiblilty for my leds, but here comes the PWM in place.
Whan i want to do is to run a Led matrix (11x8) and with PWM only run 8 LEDs at the same time, So it would run the LEDs at 1/11 of their power. after one and other. So Row1, Row2, Row3 etc...
This is done by running the 8 colums on the mux and the 11 rows on the Teensy 3.1 PWM ports.
On top of this im going to have ofc a Tenkeyless keyboard on 6x17 matrix. (and thus making me use a total of 37 pins and pads on the Teensy, 39 with the addition of GND and 3.3V to the Mux).
Yes im aware that this is pushing the limits of the Teensy but hey why not?

Ive attached a copy of my scematic of the beast. (there is a 16ch mux on that but i realized that i don't need a 16ch one in the middle of building and cba to change it

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schematic.png (512.25 kB. 13050x6483 - viewed 156 times.)
My question is this:
Is this PWM config even possible with current libraries?
Where can i find a keyboard config for the Teensy 3.1? Ive found the ones that is used to set the teensy to continously send some keyboard commands, but i want to use it as a normal keyboard.