Don't know about HiWin track - but I took some steel bar stock, aligned it, clamped it, then carefully drilled and tapped through each hole using allen cap machine screws that fit my track.
A lot of effort as you say, but it is one length of T-Nut like bar. The bolts were loosely fitted, and the track slid into the 8020. It was useful to tighten only some until I got the system square.
Your approach with many T-Nuts should offer the same set up - but a lot of work as you acknowledge. And it should work - IMHO.
Sorry no pics to offer and the ones in my gallery don't show it very well either.
Hope that helps.
hmmm maybe that is something ahern could offer from his cnc store????