So I did the Thermal Odyssey 1.5mm repad, First attempt was the back, it mostly stopped the memory from throttling during eth mining, but only dropped a few degrees:
Then I did the front - and like a total idiot managed to snap the lower fan's ribbon cable clean in two when I separated the pcb!
I'm used to doing this kinda work and watched the teardown videos, but for some reason I got into my head that only two headers needed to be disconnected, and completely forgot the third! I was so damn sure I didn't check (otherwise I would have). It snapped so easily I didn't even notice until much later.
of course (it seems) you can't buy the FE fans anywhere yet, so I had to fix the cable.
I managed it after a bit of research. I never thought FCC cables can be fixed - they can, but it's a bitch. You can reveal the traces and tin them, but they would not 'bridge' ie. connect across the gap. I ended up soldering hair-thin copper wires across the gaps:
super-tricky and took a few attempts, but I got it in the end, and now it's humming away mining (phew):
So, before I was hitting around 106degC mem mining Eth (after the rear panel pads only). For the front I only replaced the VRAM pads with 1.5mm Thermalright Odyssey and left the rest stock. Now mining @ 94degC - a worthwhile 12degC drop (~16C overall).
Of course I only had basic thermal paste so now the die is 3C hotter, I'll probably fix that soon.
so yeah, _3_ headers on the 3080 kids

. Oh and that damn light-guide, that you have to insert _before_ fitting the PCB to the heatsink (it lives under the PCB).
Interestingly, the single SMD LED for the V-shape is an RGBW (ie. with a separate white chip - didn't take a pic).