So, a little update from my side for whoever is interested in this (and again, thanks for reading).
Been playing with the box 2-3 evenings every week since my last post and still impressed by it (considering what I plan to use it for), yet not there where it should be yet.
Bookworm (some various archive images I found online) works fine, and I can install OMV via armbian config, although performance is bad and I’m talking here about applying changes using the UI - like it takes whole minutes, plus some expected issues for the 2.5g interface.
Trixie, all good installing, OMV fails from armbian config but works fine via the OMV installation guide from their site, it’s snappy in applying changes, like not instant but just a few seconds. The 2.5g interface is still an issue and while I can get good results on writing to the box after trying various fixes found online (like a 4gb file write is just fine, the interface crashes and I lose connection while copying from it back to my pc). This doesn’t crash the device completely, still works fine on the 1g interface, and accessible, so from my point of view is more of a perf issue than a stability one.
Overall, still happy having this box, but man you do spend a lot of time getting things right, an obviously I’m a newbie.
Thanks for watching!
(Just for clarity, my 1g interface is connected to my 1g router, and the 2.5 one directly to my desktop to a 2.5 usb network card, and this set up was working fine on buster)