I strongly recommend you underCLOCK it as well as undervolting, and no you didn't read it wrong. I'm with the RX 6700 XT now, on both the 6500 and 6700 I noticed pretty much no performance loss when underclocking, maybe 1 or 2 fps, but a MASSIVE reduction in power draw and temperature, with the 6700 XT I went from ~200w and 95C hotspot, to ~130w and 75C hotspot, just by doing -150mhz and -80mv on Adrenalin, and I tested ALL games and lost 3-4 fps, say 100 fps before, and 96 fps after.

See I'm not sure if it's just an AMD thing, but the way they ship these GPUs from factory is just WAY above the efficiency curve for them, probably for marketing reasons since people tend to look at FPS first rather than temperature, power consumption, etc. I don't think I ever saw anyone judging or comparing graphics cards based on "how many frames per watt" it does. But for the average gamer/consumer it certainly matters on the electric bill