NCE PowerCab - Possible to Reprogram Key Values for F13 thru F28? - Model Railroader Magazine

Per a post I made a while back I've switched from DCS to DCC, and am now using NCE's PowerCab to run a mix of engines (two MTH & two BLI) on my 5'x9' layout. I've managed well enough at reading the NCE PowerCab manual that I've been able to re-map CVs to harmonize a few of my heavily-used functions across the different engines, which sure simplifies operating multiple locos simultaneously. 

(For example--BLI uses F9 for startup/shutdown; MTH uses F3. Since I find it easier to re-set CVs on the BLI engines, I've set them to use F3 for startup/shutdown also. Now I don't have to remember two different keys for that function, and recall which is which for which... ditto for grade crossing signaling, etc.)

So far so good. BUT:

Now I'm looking for a way to move my most commonly used functions to the easiest-to-access keys, so I'm not having to hit as many keys to trigger those functions. For example: I've harmonized the CVs so that, when the engine is not moving, F22 will arm the coupler slack sound on any of the four engines. Still, I have to press three keys -- [Option]->[Option]->[2] -- on the PowerCab to get to F22.

Per the NCE PowerCab Manual 'Cab Setup' section steps 10 [on page 21 in the pdf version I have] you can re-program the value for each 'key number' [shown on page 22] to re-map which actions and/or DCC functions are triggered by a particular key. The possible key values are shown in a table underneath Cab Setup step 10.

No key values are shown, however, for F13 through F28.

So, NCE PowerCab users: Is it not possible to map functions above F12 to be triggered by a single key?

If it is possible, I'd appreciate a pointer to a table for the key table values for F13-F28, or a how-to primer explaining how I can determine those values.

Otherwise, I have to reset a whole lotta CVs to move those commonly-used functions down to F0-F12...

Thanks in advance for any and all helpful replies!

-Rick