Honestly, I'm not sure there's much value in designing things that need to be printed with a 0.1mm nozzle. I'm an old fat guy from the old school. I can tell you that those tiny details are things that the people using the things you design are never even going to see. Not to tell you how to do what you do from a design perspective, but I do have some experience from a user's perspective.
If the insides of your models looked like the outside it would be sufficient. Personally, I was thinking of using TinkerCAD to build towers out of individual blocks. There is a fantastic series on YouTube about Guedelon castle in France that is six hours of videos about how a real stone castle gets built. If you haven't heard of Guedelon you are really missing out. It's wonderful!
I think I actually played with the Chainmail rules a couple of times when I was a kid. What system are you using? Are you designing for 28mm fantasy RPGs or for large medieval combats?
The thing I love best about your designs it that they are pretty realistic. Except maybe the arrow loops which I've never seen with a large opening at the top and bottom (https://en.wikipedia.org/wiki/Arrowslit). They look nice, but I think they're not really practical. I'm sure I could be wrong and that you may have a historical reason for designing them that way.