Just my experience so far as I am working some loads for my 32 and have had limited time to try them out. So far my experience has only been with 78 gr. cast RN and Sierra 90 gr. JHP.
Some "over book max" loads with the Sierra's and Blue Dot showed inconsistencies even though I hadn't hit the "peaky" point of the powder. In a 32 that spot can be hit and past real fast. Some loads of "real hot" W231 showed me when I hit .1 - .2 gr inconsistencies by sudden flat primers in a group of otherwise normal primers. All charges weighed on a RCBS digital scale BTW. I haven't been afforded the opportunity to fire off the AA#7, Longshot, and Herco loads yet. But I am betting that something in this speed range is as slow as I want to go and get the best bang out of this cartridge.
H110 / W296 is a powder that is meant to be run hard and has a limited window of pressure that it works properly in. That range will be real small with a 32 H&R and you can be under / over that range in short order. Personally I won't bother with those powders for this application even though I have them.
I haven't started experimenting with the 115 gr. cast that I have but I am still betting on the Blue Dot level speed range to be the best overall powder
speed for consistency.