It’s one of my favourite things about my crosswired brain (and a lifesaver during episodes of insomnia) that I’ve always had significant control over my hypnagogic state, though it wasn’t until a few years ago that I found out what it was and that not everyone can (or maybe they just don’t know how?)
I do similar for software design. Not explicitly visual although it does feel like the same brain space - shifting, sliding, rotating as I do with visual imagination, until things seem to fit or resonate.