I had a 4455TC in 2011 and reported some results with it on here back then. Unfortunately it got fried later that year by accident, my fault I think.
Anyway, it only became a two-stage if it had the TC option, otherwise it was a single stage 13.6. It did 14.2 in "boost" The TC was based on a "nominal" temp of 60F ISTR. Randy had a bunch of graphs etc linked for it. It did a good job recharging my 6s, can't remember about bubbling amounts.
I posted about playing with the TC sensor in ice cream to get the voltage higher. It did 61ish amps (rated 55) with short fat wiring to the batts, as seen on the Trimetric. I did crank up the pot to make boost 14.8, which also made float go up, so I had to use my OEM 7355 for Float. Drove Salvo crazy when it (at 14.8) did as well or better than his beloved Iota 55 amper :)
I ended up with PowerMax as a replacement (adjustable voltage ones)