Hello! You can use the asset in any way you want as long as you do not sell the assets as I do on my itch.io. This includes modified assets and the original ones.
Of course! By project I meant a game that uses some parts of slightly altered UI, not reselling the asset as an asset pack, that would be wrong! :) So if I understood you correctly, using it in an adjusted version in a game should be fine, no matter where it is distributed (if it ever happens, that is) :)