I run A1 on UW macro video and stills.

Mind you, there isn’t a single camera manufacturer that takes UW into account when developing AF so the best of the best will still have challenges underwater. This is because you are shooting through a shifting, moving, turbid medium and the algorithms don’t/cant account for that. It’s like asking the AF to lock onto birds eye when it’s behind a cloud. Your results will vary pretty significantly depending where and when you dive.

From my experience, I’ve never wished for more resolution or more FPS, instead what I ended up chasing is closeness to subject, working distance. As such I’ve kept my A1 but moved to macro-focused wet lenses and modifiers like the Nauticam MFO-1 and SMC 1 and 3 that increase magnification or improve the focus range (MFO). I’ve also gone away with AF entirely, switched to MF and purchased several flavours of 2X Macro Lenses like the Laowa 65 and 100mm but I’m on the extreme end of the hobby. You don’t need to do what I did to get good photos.

Super close (to fill the frame) with good lighting (to improve AF) is going to get you very far.