The following examples are how I programmed my MD600v3 RB keyboard.
My layer usage is
- layer 1: primary typing layer
- layer 2: lock-navigation layer
- layer 3: for testing ideas without messing up layers 1 or 2
The following examples assume that the Fn key is in the default location.
Procedure for remapping Fn key to default location
1. Press the current Fn + L_Shift for about 3 seconds (LED 3 blinking red).
2. Press the current Fn key.
3. Press the default Fn location.
Example 1: Rearranging left-column keysThis example moves Tab and Esc down and eliminates CapsLock.
Default-layer left col:
ESC      1
TAB      Q
CapLock  A
L_SHFT   ZNew layer-1 left col:
`        1
ESC      Q
TAB      A
L_SHFT   ZAdvantages compared to the default layer
- not press Fn to type '`' and '~'
- Esc key closer to home row (for users of the vi editor)
- not accidentally press CapsLock
Procedure for programming left-column keys
1. Select layer 1.
   - Fn + < (LED 2 red)
2. Enter programming mode.
   - Fn + R_Ctrl (LED 3 blue)
3. Program macros.
   Move Tab and Esc down (which also eliminates CapsLock)
   - program '`' onto Esc:                      Esc (LED 3 blinking blue), Fn + `, Pn (LED 3 blue)
   - program Esc onto Tab:                   Tab (LED 3 blinking blue), Esc, Pn (LED 3 blue)
   - program Tab onto CapsLock:         CapsLock (LED 3 blinking blue), Tab, Pn (LED 3 blue)
   - program Tab onto Fn + CapsLock: Fn + CapsLock (LED 3 blinking blue), Tab, Pn (LED 3 blue)
4. Exit program mode.
   - Fn + R_Ctrl (LED 3 off)
Test all changes.  Online keyboard testers are a convenient way to test non-character keys like Esc. 
https://www.keyboardtester.com/tester.htmlExample 2: Disabling InsThis example disables the insert by mapping ';' onto Ins.
Procedure for disabling Ins
1. Select layer 1.
   - Fn + < (LED 2 red)
2. Enter programming mode.
   - Fn + R_Ctrl (LED 3 blue)
3. Program macros.
   - program ';' onto Ins: Fn + ; (LED 3 blinking blue), ;, Pn (LED 3 blue)
4. Exit program mode.
   - Fn + R_Ctrl (LED 3 off)
5. Test the change.
Example 3: Implementing vi-style navigation keysThis example adds navigation keys similar to the vi editor's h-j-k-l keys.  
Default right-hand keys that will be programmed:
     Y    U    I    O
     H    J    K    LRight-hand navigation keys after programming:
     HOME PGDN PGUP END
     LEFT DOWN UP   RIGHTProgram navigation keys on layer-1 FnProcedure for programming navigation keys
1. Select layer 1.
   - Fn + < (LED 2 red)
2. Enter programming mode.
   - Fn + R_Ctrl (LED 3 blue)
3. Program macros.
   - left  arrow: Fn + h (LED 3 blinking blue), Fn + j, Pn (LED 3 blue)
   - down  arrow: Fn + j (LED 3 blinking blue), Fn + k, Pn (LED 3 blue)
   - up    arrow: Fn + k (LED 3 blinking blue), Fn + i, Pn (LED 3 blue)
   - right arrow: is same as default
   - Home: Fn + y (LED 3 blinking blue), Fn + h, Pn (LED 3 blue)
   - PgDn: Fn + u (LED 3 blinking blue), Fn + o, Pn (LED 3 blue)
   - PgUp: Fn + i (LED 3 blinking blue), Fn + u, Pn (LED 3 blue)
   - End : Fn + o (LED 3 blinking blue), Fn + n, Pn (LED 3 blue)
4. Exit program mode.
   - Fn + R_Ctrl (LED 3 off)
Disable keys on layer 2Navigation on layer 2 is similar to layer-1 Fn navigation keys but without having to hold down the Fn key.
To avoid unintentional edits while locked on the navigation layer, disable all keys on layer 2 except for:
    Esc
    L_Shift    Default Layer1 Layer2 Layer3 R_Shift
     L_Space bar                     Pn  Fn  R_CtrlThere is no way to disable keys on this keyboard.  However, keys can be assigned a harmless value such as Esc.
Procedure for programming Esc onto layer 2 [key]s
1. Select layer 2.
   - Fn + > (LED 2 green)
2. Enter programming mode.
   - Fn + R_Ctrl (LED 3 blue)
3. Program macros.
   - Esc onto [key]:  [key] (LED 3 blinking blue), Esc, Pn (LED 3 blue)
4. Exit program mode.
   - Fn + R_Ctrl (LED 3 off)
Disable keys on layer-2 FnDisable all keys on layer-2 Fn except for:
    Layout
    L_Shift    Default Layer1 Layer2 Layer3 R_Shift
     L_Space bar                     Pn  Fn  R_CtrlProcedure for programming Esc onto layer-2 Fn [key]s
1. Select layer 2.
   - Fn + > (LED 2 green)
2. Enter programming mode.
   - Fn + R_Ctrl (LED 3 blue)
3. Program macros.
   - Esc onto Fn + [key]: Fn + [key] (LED 3 blinking blue), Esc, Pn (LED 3 blue)
4. Exit program mode.
   - Fn + R_Ctrl (LED 3 off)
I could not program these five keys: Fn + Tab (Layout), Fn + r, Fn + t, Fn + g, Fn + b
Program navigation keys on layer 2Now that most keys on layer 2 are harmless, program the navigation keys.
Procedure for programming navigation keys
1. Select layer 2.
   - Fn + > (LED 2 green)
2. Enter programming mode.
   - Fn + R_Ctrl (LED 3 blue)
3. Program macros.
   - up    arrow: k (LED 3 blinking blue), Fn + i, Pn (LED 3 blue)
   - left  arrow: h (LED 3 blinking blue), Fn + j, Pn (LED 3 blue)
   - down  arrow: j (LED 3 blinking blue), Fn + k, Pn (LED 3 blue)
   - right arrow: l (LED 3 blinking blue), Fn + l, Pn (LED 3 blue)
   - Home: y (LED 3 blinking blue), Fn + h, Pn (LED 3 blue)
   - PgDn: u (LED 3 blinking blue), Fn + o, Pn (LED 3 blue)
   - PgUp: i (LED 3 blinking blue), Fn + u, Pn (LED 3 blue)
   - End: o (LED 3 blinking blue), Fn + n, Pn (LED 3 blue)
4. Exit program mode.
   - Fn + R_Ctrl (LED 3 off)
Remap the Fn key onto the left space barBefore remapping Fn, test all layer-2 keys on 
https://www.keyboardtester.com/tester.html.
Now that all macro programming is done, remap Fn key on layers 1 and 2.
Procedure for remapping the Fn key onto the left space bar
1. Select a layer.
   - layer 1: Fn + < (LED 2 red)
   - layer 2: Fn + < (LED 2 green)
2. Hold Fn + L_Shift for 3 seconds (LED 3 blinking red).
3. Press the Fn key.
4. Press the left space bar.
Example 4: Turning off RGB backlightingProcedure for turning off RGB backlighting
1. Cycle through LED modes until LED backlighting is off.
   - Pn + 4