This is good food for thought, I appreciate the replies. A few ~random thoughts/explanations:
Withing reason, I'm not concerned with the cost. Which is fortunate as, yeah, I use Griot's mixed as per what Spilchy posted.
I've thought about adding some rinseless to the regular wash bucket, might do that for the added lubricity.
Ah, didn't realize that these rinseless washes won't foam. I noticed the low-sudsing nature of my QEW but didn't give it much thought. But note that the actual *foam* isn't of much importance to me as long as there's sufficient lubrication and encapsulation along with effective cleaning. The way I wash the foamgun provides constant lubrication and flushing; I don't spray the foam on and care (much) about it dwelling/clinging the way some people do.
As to "why do it?", well, other than asking out of intellectual curiosity, I wouldn't mind a way of simplifying the washing of the Blazer, especially the roof.
As it is, to wash the roof I have to (deep breath...here goes): position my work platforms on each side, step up and do ~1/4 of the roof with the BHB/foamgun, step down, rinse BHB, redunk in wash solution, move platform back/forth, step up and do the other 1/4 of the roof, step down to drop BHB in rinse bucket and grab hose, step up, rinse off the half of roof that I've just washed. Walk around Blazer and repeat process on other side. Go back to first side and repeat the whole process using mitt/foamgun. Move work platforms out of way. Wash rest of vehicle. Move work platforms back into place to dry roof. Move work platforms back out of way to dry rest of vehicle.
If I could do the roof from wash to dried without having to move the work platforms (more than is required to reach the whole roof) it'd make the job a lot easier and I could just move them out of my way for good after doing the roof. Or at least that's what I was thinking yesterday when I did it.