Looking further into it, the real problem is the connection between the GPU (and possibly the caps). Like quite a few older laptops, the heat sink itself simply isn’t designed to be flush against anything but the CPU, leaving a 2-3mm air gap to the other. This was formerly bridged by thermal pads, which were by now a hardened crunch-peanut-butter consistency mess. They can’t be directly bridged with just thermal paste unless it’s very thick paste meant to replace thermal pads or a copper or aluminum shim and regular paste. I don’t have any pads and I’m not sure I feel like ordering any (though I might). I tried making some copper shims, but getting them flat enough isn’t easy; they don’t just need to be flat as in “doesn’t look curved or pitted” but flat as in “polished to a shine, and not from a coating”. I’ve experimented with a few sources of copper and played a little with attempting to melt or anneal it first but I come up way short, the thermal compound doesn’t bridge the further gap. Until I have time to get that right, it’ll have to be put on the shelf :-(.