I got started on this new bench project yesterday, and managed to make some real progress. Here is one complete set of legs for the breakdown bench.

I have the other leg assembly mostly done, but one of my support beams broke apart, and I had to start over on it.
Even with the band saw for cutting tenons and the mortising machine, this kind of joinery is time-consuming work. Cutting the mortises in the benchtop pieces might be done some other way.