2-4 hours for me on Fedora (AMD). This is with media consumption (video mainly) and I haven’t tested it for productivity yet cause uni is on break. I’ve been trouble shooting this to try and get better performance because I have a feeling Flatpaks may not be as optimised for hardware acceleration. For the most part though, general web browsing and whatnot does not seem to hit the battery at at all really.

I use one of the Dell Display Link docks (WD19) with 2 DP monitors and it works no issues. I made a post a few weeks ago asking a similar question so you can probs have a look through that thread.