I agree that classical NATO counters might not fit this game perfectly, but I certainly would appreciate a way to customize the strength plates. A common impression I get is that custom skins are often used to mark and identify units, e.g. to tell tactical bombers and fighters apart. Some players do...

Just click the box twice so it shows a checkmark, then click "apply".

Clicking the box only once places a square inside it which AFAIK means "no change". It is only useful when batch editing multiple selected units / tiles.

Will it be possible to mod the design, content and / or behaviour of the strength plates? I would like to e.g. - lower the plate opacity for units that don't have actions remaining - add a little symbol inside the plate that indicates unit specialization (e.g. paratrooper, mountaineer, engineer...) ...