Something that is asked very often in different social media channels is having split leaderboards between PC and mobile devices. I understand this is something that has to be deeply investigated and won't just be changed immediately, but part of the issue is as well the lack of transparency, that gives the impression of unfair competition between both platforms.

Since controlling the game is inherently easier with key presses than with drawing abilities, I would propose the following:

On the leaderboard, please just add an indicator "keyboard" or "touchscreen" for the ranked trial. Just that.

Note I'm not asking for an indicator that says Windows vs Android/iOS/Fire OS. That's because for some strange reason, mobile versions of the game actually accept key presses too. So connecting a bluetooth keyboard to your phone, or using an emulator on PC means you can cast abilities on the other platforms as well with the [1]-[3] and [Q]-[E] keys. Because of that, cheating the system could still exist. However a flag that says "At least 1 keyboard press event was registered by the game during this ranked trial" would be enough, and would be a very helpful way of showing on the leaderboards who are really the top players, and who just have the advantage of playing on a different platform than the rest.