How to know which settings to keep to move to a new computer version

Don't even think about migrating the installation itself. It's asking for problems. Do a fresh install.

Save out custom actions, brushes etc that can't be easily recreated. Store them in a safe place and reload in the new installation.

Other than that, I would recommmend not migrating settings and preferences. Yes, I know it's very tempting and very convenient, but preferences are rewritten on every application exit and are therefore very vulnerable to corruption e.g. with irregular shutdowns. Small errors accumulate! The preferences contain the entire application configuration, not just your own user settings, and corrupt prefs can cause unpredictable and strange behavior.

A new Photoshop version has new code, and the old settings may not mean exactly the same thing in the new version. If you have small accumulated errors, that may suddenly blow up.

I always take the opportunity with a new version to start with fresh preferences. It only takes a couple of minutes to set up, and those minutes may be well spent.

Some say Apple Migration Assistant works well enough, but I prefer to do a fresh install when I get a new computer. For Macs, the age of the old computer can be a major factor. For example, if moving from an M1 to an M3, those are similar and new enough that maybe Apple Migration Assistant will work OK. But if moving from a 2014 Intel-based Mac to an 2024 M3, the differences in hardware and OS are so large that a fresh install would probably work better. The 2014 may have a lot of old Intel software that might not work if migrated to an Apple Silicon Mac 10 years newer.

It’s hard to recommend which settings are the most important, because everyone’s needs are different. Some must preserve their custom keyboard shortcuts. Some cannot lose the actions they have carefully built. Others need their custom vector shapes. Painters must bring over their custom brushes, photographers might need their custom adjustment layer presets.

Read through the list of settings in the article below, and for any you want to transfer, note its location, and copy it to the new computer.

Preference file functions, names, locations | Photoshop

First of all always install Adobe applications fresh on a new computer as migration never gets all the bits and bobs because Adobe scatters files all over the drive.

As to what to copy over, it of course depends on how many add-ons like actions, patterns, etc you have.

Other things like any custom Workspaces are also considerations.

You'll still have to open the Photoshop Preferences and make sure all the settings are right, even you were to copy over the Photoshop preferences files.

Plugins should be reinstalled on the new computer and not copied over.

If you old Mac was Intel, then some plugins may not work on an Apple Silicon M1 machine.