With the Audeze HQ app for PC/Mac
see: https://www.audeze.com/pages...
also available for mobile (Android/iOS)
e.g. in the google playstore: https://play.google.com/store...

there are currently (status: Audeze HQ App v.3.1.126) 6 predefined presets and 4 custom presets that can be adjusted in the EQ as desired. Once set, these should also be retained in PS5 mode.

Since Audeze was bought by Sony not too long ago,
See: https://hifi.de/news...
I can well imagine that there will also be native Playstation apps for it in the future.
Whether it will still be enough for the Maxwell to be compatible is another question ;).

First of all, the quality is excellent, truly on a par with all other gaming headsets. The planar-magnetic drivers are amazing.
Then there are a number of in-built EQs that you can select directly with a knob on the headset, without the PS5 being involved, directly in the headset. To do custom EQ I think you need to connect it to the Audeze HQ software (mac or windows) - but I haven't tried that, so I suppose it's possible. Personally, I've found that the different EQs don't make much difference. Clarity and dynamics are so good from the start that, unlike lower-end headphones, it's less important (for me at least) to fiddle with the EQ.