It sounds like a good idea.
I know it is not what you are asking for, but since it is a way for those of us who support Arduino users to obtain this information, I'll mention that it can be derived from the verbose compilation output. The verbose compilation output shows the machine identifier for the board (FQBN). For example, if I have Tools > Board > Arduino AVR Boards > Arduino Nano and Tools > Processor > ATmega328P (Old bootloader) selected, then it will show this:
FQBN: arduino:avr:nano:cpu=atmega328old
The format of the FQBN:
<vendor ID>:<architecture>:<board ID>[:<menu ID>=<option ID>[,<menu ID>=<option ID>]...]
The arduino:avr part of the FQBN tell us they are using the "Arduino AVR Boards" platform. The nano part tells us they are using the "Arduino Nano" board from that platform. The cpu=atmega328old part tells us they have selected the "ATmega328P (Old Bootloader)" option (option ID: atmega328old) from the "Processor" menu (menu ID: cpu).
The next lines of the verbose compilation output are also useful in that they contain the version number of the platform:
Using board 'nano' from platform in folder: C:\Users\per\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.8.6
Using core 'arduino' from platform in folder: C:\Users\per\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.8.6
(note the 1.8.6 at the end of the path)