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 nic…
Also with an OLED, running at 20% brightness indoors, I'm able to get around a 7-8 watt power draw using the lowest AMD-pstate with a relatively modern Linux kernel.