Same machine here as well, running the latest Ubuntu (23.10) power profiles do work but auto-cpufreq is way more effective in increasing battery runtime for me.

I can get ~6h of runtime (~10W draw) if i mostly just code in VSCode + some browsing, with display at 1/3 brightness and the code being executed remote. Went with the OLED panel, so that definitively doesn't help battery runtime, but damn those colors are nice :)

I wish they would fit in a bigger battery or do some more tuning so that some cores could actually turn off if they aren't used, id happily accept the spool up time for big jobs, if this could increase the battery runtime a few hours/allow for higher brightness. What kind of runtimes/draws are you getting?