Not on this device but I have on a PinePhone before, works just fine.
Ideally it would use the desktop shell on the external monitor though, that sadly doesn't happen yet (but is planned for the future).
I mean, not being able to delete some files because they're read-only and what not doesn't mean it's less open. You can't do that on an immutable distribution either but I definitely still consider them "open".
At postmarketOS we're planning to also offer an immutable option in the future. We'll always keep a mutable option around for people that want it but by default we'll ship the immutable variant to our users because we can guarantee stability and safe updates way more. Then you won't be able to just delete system files either.
We definitely have a housing crisis, but taking Amsterdam as an example is not representative for the entire country. That city is way more expensive than all other cities here and has jokes about it for ages, not just due to the current crisis.
