I had similar issues with my first (and only so far) set of modular pieces. After trying and failing with several attempts, I decided to lay down one grid for all my pieces (for example 256x256 units). I then made modules (for example a wall) that have exactly this length and a certain thickness that is suitable for a…
Oh I've read that before from the wiki as well as some of Philipk's and the Unreal engine articles on the subject and such. A lot of tutorials and information out there don't really talk of cases that I had mentioned though which extends onto designing how wall are set up or having contact points beyond just the sides that…