hmm, i've played around a bit with level design in the past and honestly Arcol wouldn't be that great a fit. I like Probuilder in Unity for that, I think the key to any good workflow is immediate changes and fast iteration, so you really want something that's pretty tightly integrated into your game engine.

It could be useful for greyboxing or even just generating some rough shapes though. We do export GLTF which is easy to get into game engines.