Yeah I missed the announcement originally, still have one box on 3.2.2 which I'm not looking forward to upgrading to 3.3.1 solo.
Luckily for me everything else was on 3.3.1 MU5 so I've only had the basic patch installs to deal with (had been doing them on some 8400s for a while to save time as the support process took a while to organise).
I too am avoiding 3.3.2 for now, I normally don't go near new base versions until MU2/3 appears. Although as they have just announced EOL of all the 3PAR range I'm not sure how many updates 3.3.2 will get (it will be the last 3PAR OS version).
The basic P patch installs are pretty straight forward, do them in order (typically) and check the release notes for any additional steps (normally just for disk/cage firmwares).
I've done P155 but still have P156 to do, I think the notes for P156 mention that it includes P155 so you may not have to install that separately. However doing both might be better practice.
SP updates have also gone smoothly for me, they do worry me a little more though as it's rebooting a physical box and we are still WfH here.
Although the support lead updates are now chargeable anything that goes wrong during the process is still meant to be covered, so they should be able to swoop in and save the day if something doesn't go to plan.
If you're not familiar with the SP GUI or not seen the update process before there are a couple of docs from HPE with basic screen shots and instructions.
Main bits I do are to run the readiness test options before each patch and untick the update hardware box (can't remember the exact name). That's what I've seen support do in the past, normally if a firmware needs applying you can do it after finishing all the patches rather then having to wait in the middle. The release notes will mention that an admithw command needs to be run, so you can just do that as instructed after from the CLI, where you can keep an eye on it as it progresses.
Also remember to install the latest Upgrade Tool patch first (think U040 is newest atm), same method as doing a P patch install, it should include all the latest pre-check scripts to help point out anything wrong/missing before patch installs.