Great performance, stability and general useability as per 30.08.2024 with only two caveats:

Ensure that proton version 6.3-8 is forced. This will give the most stability and performance, while preventing the "cursor on screen when controlling camera" issue occuring at current experimental versions of Proton.

Enable the ingame setting "Open lotro store in external browser" under UI settings. This will prevent the only crash I had when trying to access the store using the internal browser.

Aside from that I have had no issues as per testing over a period of three days.