Personally I'd find it easier and more intuitive to use if I could press the X/space/enter/0/1/2/3 keys on the active tile. This would mean either disabling the red-highlight keyboard selected interaction while your mouse hovers (maybe in favour of a different colour outline), or having it be a separate option as to how you want to interact.
Being able to mouse interact to reveal tiles but not to mark is a bit intuitive (e.g. in minesweeper you can mark with right click).
Another option would be to allow right-clicking in each of the 4 quadrants of the tile to toggle the relevant flag. I don't know if I'd find this more or less usable, so other opinions welcome (maybe it deserves both being tried out!)
I may (or may not) try to address this in my fork.
Personally I'd find it easier and more intuitive to use if I could press the X/space/enter/0/1/2/3 keys on the active tile. This would mean either disabling the red-highlight keyboard selected interaction while your mouse hovers (maybe in favour of a different colour outline), or having it be a separate option as to how you want to interact.
Being able to mouse interact to reveal tiles but not to mark is a bit intuitive (e.g. in minesweeper you can mark with right click).
Another option would be to allow right-clicking in each of the 4 quadrants of the tile to toggle the relevant flag. I don't know if I'd find this more or less usable, so other opinions welcome (maybe it deserves both being tried out!)
I may (or may not) try to address this in my fork.