I should qualify that I have never played another Voxel game so maybe this is not helpful. I have also not messed with the new creative beta on Boundless… So again …
I was messing around in the updated Fortresscraft Evolved game and found that their offline creative mode might be a nice pre-engeneering supplemental tool for Boundless. You can see it in action here
The aspect I would love to see implemented into Boundless would be to use the totem to cast a line of whichever blocks are in your offhand for building efficiency. You’ll see what I mean in the video. Anyways, just trying to be helpful.