Apparently ryzenadj doesn’t work with the ai 300s jet but once it does you can literally set a skin temperature target (and min throttle level) and it’ll throttle to meet that. The 7840U kneecapped to 10W still has a surprising amount of performance.
The 7840U being more mature is definitely a reasonable argument at this point, especially since it’s much better price/performance than the ai 300 series (unless you actually need the ai engine, the ai 300 series sacrifices a lot for that).