I think it’s hard to determine what qualifies as “3rd Gen” when discussing PC guns. Here’s what I mean.
You could argue the 845 is a “3rd Gen” simply because it also used the one-piece 3rd Gen grip. At the same time, you might argue that a 952 is not a 3rd Gen because it does not use the one-piece grip and if anything, it corresponds best with a Model 52, which would be a 1st Gen pistol.
So for me and for the way I frame and care about the information and discussion, I simply won’t ever call -ANY- Performance Center pistol as ANY 1-2-3rd Gen. Since they use different barrels, different safeties, different trigger parts and different hammer parts and use a Briley spherical bushing — for me, a PC gun is exactly that, a PC gun and not any 1-2-3rd Gen.
With that said, there exists one odd pistol that is not a PC gun but would be considered a 3rd Gen that is also a single action only pistol. That would be the Super 9. It’s slide mounted safety is NOT a decocker and would be best described as a hammer block.
In the 1st Gen series, the 52 is single action only. Again, a hammer block safety. And in the 2nd Gen group, the .45cal Model 745 again uses a hammer block safety, no decocker.
In reading your post again, you asked if it was no decocker or “just disconnect the innerds”

Actually, no, it does not disconnect anything inside.
On the 52 or 745 (or 952, 845, 4006 Limited, 3566 Limited, PPC-9 or the Target Champion variants of those models, you can rotate the lever to safe and still squeeze the trigger and drop the hammer — however applying the safety locks the firing pin in place and also blocks the hammer from hitting it.