Handwired Planck Piezo speaker?

[OhManIAmWorried]

Hi guys.
I'm in the process of building my first planck, handwired, with pro-micro.
As I'm about to modify qmk files, I wonder if two remaining pins on pro-micro can be used for piezo speaker. If so, do I need to include resistors in the circuit? If there are posts of people doing such stuff, please, share some links.
Otherwise, I'd like to know for sure, which lines should be commented, and which flags and macros should be modified for planck firmware to forget about this function.
Any help is appreciated, thanks!

[OhManIAmWorried]

Upd: changed pinout in planck/config.h, but after compiling and flashing, kb works as if pinout wasn't changed, so I get keys in wrong places, most of which doesn't work.

[OhManIAmWorried]

Upd: after some tweaking I have my board recognized as HID keyboard with no com port to play with. What a fun ride