Not OP, but can only speak from my experience: Installing a second WM/DE usually messes up my install, as quite some stuff is just from one GUI framework, so I don’t have to have to much stuff installed.
Also getting rid of it afterwards always wasn’t as easily possible.

I completely get trying out a WM y firing up a VM. You could even just boot the live USB stick to check it out.
But changing my working install just to try something (and then have to clean it up again) wasn’t working out for me in the past

I’m also happily running Manjaro on my new Framework 16.
Even the fingerprint sensor works fine - although I’ll still need to tune LightDM a bit, so I don’t have to press enter.

Do you have any tips what you have done further or any resources?

At first the WiFi wasn’t working and is still a bit unstable - like isn’t available as interface after booting and I need to toggle flight mode.
But it seems a newer kernel (6.10.6-10) mostly fixed it.

Also sometimes coreboot seems to take some time. But only every 10 boots or something.

Thank you very much for those insights!!

Would you give your perspective anyway, as I would be quite interested, although I’m not the one you talked to?