[Author here.] Indeed, sectorFORTH (as I have mentioned) was the primary inspiration and guide for this project! Ironically, in some places I even had a rather different design which converged on a more sectorFORTH-like design - it's really well put together.
I've removed some primitives further from milliFORTH, but I haven't touched the arithmetic base. I hadn't seen those issues on sectorFORTH though, very interesting - I will look into it!