Why no per-key brightness on launch_1?

[ctrlcctrlv]

Hardware or software limitation?

[leviport]

I believe it's a limitation of the ROM space on the ATMega 32u4 controller used on Launch, since storing the brightness level of each key would probably consume a fair bit of space. I've seen a few people manually customize and flash their own version of QMK firmware to slim down the the amount of space the firmware takes. It would take me a while to find where to start, since I don't play with non-default LED settings much, but I'm guessing that one could manually configure the backlighting scheme they want, along with disabling extra QMK features that might also consume ROM space.

If you decide to take a swing, I'd love to hear what you find out! Also, the QMK docs might prove useful in such endeavors: https://docs.qmk.fm/