You know of a way to do sq1BLD without going to cubeshape first? I'd be interested to hear it.
I do (but just theoretically, no more than you), but that's not what I said. What I said was you don't need to on-the-fly trace pieces through several moves until cube shape. You could *learn* transition tables from all shapes to cube shape *beforehand*. Once you've done that, it should be much easier and not as time-consuming. It's a lot to learn, of course. But it's just one extreme end, learning transitions for all shapes. The other extreme end is knowing only the cube shape. One method between those two extremes is to learn transitions for a subset of all shapes so that any shape is at most one move away from one of those, so you have very little to trace during the attempt.
Thanks for bringing this up, Stefan. This is exactly what I had in mind when I said I have a method I want to try. (And I'm talking about the extreme end. It's simply not all that extreme. Compared to the big pi memorization efforts, it's, well, as easy as pie.

) I'm hoping my first successful square-1 BLD solve will be easily stackmatted. Truth is, I'm expecting to be disappointed with anything worse than 5 minutes. And it should be possible to be pretty much as accurate as with 3x3x3 BLD.