I think it is ok to donate for infrastructure at least, and that is the bare minimum.

It think that scope of your proposal should be extended to include older devices as well (e.g. application porting if not advancing features).

Bare in mind that small contributions like this will work as long there is existing hardware used be contributors. For future we need a bigger sponsor (e.g. hardware/software vendor). Without that I think it is not feasible to fund paid development, except for relatively small bounties.

Community contribution should be a primary work horse.

Merging with existing established projects (debian, gnome, etc.) would also make sense in the long run.