I think mine only took maybe half a mag, but I don’t fault you, the adjustment is definitely different and kinda wonky. I didn’t use the tool, just an Allen key and flathead. I think there are much better sights available, and the DM mounts really help them with the HOB associated with rails. Still, the OEM sights retain the correct look of the SBR PS90, which is more important to me than absolute top performance. If I were building a rifle for serious use, it wouldn’t be a PS90 SBR in the first place.
I’ve had all of the OEM sights by now, and the black ring is hard to beat. There are push button LED variants out now though. I picked up an LED white ring/fiber optic, and the white ring is actually WAY more usable than on my old polymer white ring. Like, it’s actually serviceable in a lot of lighting conditions, whereas the earlier polymer one was all but invisible except in certain lighting conditions. The LED illumination is NICE, but I don’t really need it most of the time. The FO works pretty good.
ETA: DEF do a form 1. SBR’ing my PS90 is easily one of the coolest gun related things I’ve ever done. I never regret a stamp, but the SBR PS90 is beyond cool.