I'm in the process of comparing the spacings of the different templates. The first surprising thing I found is that although my two Magic Ball Rack 8-ball templates are identical, as are my two 9/10-ball MBR templates, the head-to-foot spacing on the 9/10-ball rack is noticeably tighter, maybe 1/8". Also the holes in the 9/10-ball rack are larger. Whether either of these differences is intentional, or still found, I don't know.I’ve done the same since 2013 or so, and will never stop. I don’t use the Perma-Rack, though - I just mark the centers with a pencil using a 15-ball Accu-Rack template, then place the clear donuts.
When racking, I use the wooden Diamond rack to quickly push the balls onto the donuts, and a couple little shifts is all it takes to feel them “lock”. Takes around 4-5 seconds once the balls are in the rack, much less tedious than easing them in place by hand.
I agree about using a triangle rack to load the balls onto a template. It's faster and easier than by hand.