@cavedweller,
1st gen had 7.4 v batteries and topped out about 47 ft lb if I recall correctly.
The Safari came out in early 2018, I believe, and raised the power with 11.1 v batteries to about the 60 ft lb area in 25 cal and 50ish in 22. We found hammer damage, the tensioning flat spring breakage and uninspiring accuracy in 25 cal so the ART program began somewhere around early 2018.
The 25 cal and later 30 cals were given the 5 groove poly with slower twist and lighter choke and started being pretty competitive. The hammer (soft steel) was replaced with case hardened unit, flat spring was replaced with an oring, and valve assembly was changed a little to insure reliability. (Note that soft steel is necessary for solenoids because hardened steel retains magnetism and soft does not) In my testing, the 30 cal was comfortable at 88 ft lb with the 50.1s and was pretty incredible with NSA 49.5s at about 90 ft lb. The 177 and 22 were considered competitive and called "ART Approved". A couple of years later, the setup menu was updated and allows control over timeout and maybe other things that mine did not have... power is unchanged, afik...
At some point, the current mags were introduced and the drive pin for the old ones retired...
A modification was discovered that would bump the power AND increase efficiency SIMULTANEOUSLY , but I have no idea if it's being incorporated into the current rifles. Mine are capable of over 100 ft lb now with at least as many shots as at 90... Also note that the original ART profiles are NOT being used but still 5 groove. I do not know how many profiles have been used on current rifles. 22s now are ART barrels to join the 25 and 30... Another note... I've tinkered with and written about the 177 poly with NSA 20.5s but it takes pl10 (of 12) on my Heliboard to send them at 975 where pl 12 would only get them to 925 before. I don't know of another rifle that might be as good with these as we're talking about full bottle pressure available behind the slug... ok, maybe other unregulated rifles of high power...
So that is the short version... I had hoped a new RW would appear that would address a couple of shortcomings but not looking likely.
Still my favorite power plant by a BIG margin...
Bob
Also... congrats on your shooting