Graphical glitches and how to deal with them

I've upgraded my rig finally a little bit so was able to run PG with Ultra settings (the video chip is NVidia GTX1660 and I'm playing on Ubuntu).

Some glitches I encountered so far:

1) Horizon flickering on the border between the mountains in the backdrop and the sky (in Serbule for example).
Workaround: Graphics - Advanced Options - Show Horizon Terrain - Disable
Permanent fix: haven't found so far

2) Brown rectangles drawn at various distances (noticed only in Eltibule so far).
Permanent fix: Graphics - Advanced Options - make sure Tree Draw Distance and Tree Billboard Distance are both set to the same value. I believe there's no reason to make these into separate settings - maybe better to keep only one so there's less confusion for players

Maybe you got some other glitches you know the cure for - please share.