Spring RTS Engine

That's correct, GMN.

However, in the sake of saving memory, and in terms of intelligent use of time, I wouldn't actually have a custom damage texture for every unit (though it would be perfectly feasible). I'd more likely have a handful of 'busted' generic textures that would be overlayed as you describe. That saves there having to be double the amount of textures (well, they wouldn't be the same size).

Eh, I figured how many damage maps were used would be up to the content creator anyway.

So, is anyone planning/willing to have a stab at this?

The best way would be to simply make your own shader in LUA and render the unit trough that, then you can have whatever textures you want doing different things. I'm thinking about adding something like this to my md5 project.