Perhaps for your own education the tip should have been that long list of conflicts. All those conflicts are because task-lxqt wants P6 packages where you seem to have P5 installed.
IMO no one should be installing ROME Plasma5. And when the next version of Rock is released no one should be installing Rock Plasma5. Plasma5 is over, as in EOL.
To be factual Plasma 5.27.11 was released 06 Mar 2024. It is still supported upstream and by OM. But practically speaking it is over. Plasma 6.1 was released 18 June 2024.
The x86_64 iso is tested. The znver1 iso is not yet tested.
If Install using x86_64 iso and then install task-lxqt there is one bug noticed. PCmanFM does not open “Computer” which is the access to the file system. Otherwise seems OK. Since you would have Plasma6 installed also you could use Dolphin file manager.
I let @bero and @AngryPenguin know we need to add that to task-lxqt for Cooker and ROME(rolling).
@Hanisch So you should have success installing from the x86_64 Plasma6 iso # 3460 and then installing task-lxqt. I believe the znver1 iso # 3461 will also work just fine but as stated I have not tested that one yet.