I hear a lot of complaints about dotnet watch, but my experience doesn't match. I just use it from the terminal (instead of running it from an IDE) and it mostly just works.
I mentioned this another comment, but the LLM requirement is more of a nice to have. What's more important is the overall experience: linux support, good trackpad, nice keyboard, battery life, screen, customer support experience, etc.
Even the ThinkPad range has a lot of variation in it and there are lots of build customisation options. I have never had a major issue with ThinkPads on Linux. I tend to spec them quite highly and keep them for many years.
I just bought a new T16 a month ago and it's great (32Gb RAM, sRGB screen, 2Tb SSD, Ryzen 7 processor). Installed PopOS in about 20 mins and everything just works.
However, as others in this thread have observed, I don't really see the point of trying to run local LLMs on a laptop, unless you want to just play a little. If you want to really play with LLMs wouldn't a separate larger box be more effective rather than trying to do it on a mobile device?