one really annoying aspect of skirmish defense is that you can build these well built, elaborate bases but you can't save them.

What i envision is that you make your elaborate base then in the pie menu there's an option to save. you could even have a prompt to name it. then the next time you load up the scene you made and saved the base in, a menu will pop up with a list of saved bases. when you click on one everything will load up just like you left it in build mode (and you'd still be in build mode after you loaded it)



it's probably been suggested a thousand times before but even using prefabs from mods it's still tedious.

Can't say much other than I agree.
I'm pretty sure using the scene builder might be a work-around for this, but that's not a real solution.

I would also love the ability to build bases in game, have some sort of engineer unit that can place structures in a certain range maybe.

I very much agree with this also. Right now there are a few preconfigured maps for you to play on though.

This should show up in the future due to the way that the Campaign mode will work. I don't think it would function without something along these lines.