No emails have ever been ignored or left unanswered. If anything, the replies may have ended up in the spam folder, or the email address may have been entered incorrectly. And why should any of this suddenly be outside the warranty?
Highjacking this reply to ask a question: have you considered the spacers in the centre of the block?
I have a Core block for the ASUS Prime RX 9070 XT and had the exact same issue: hotspot around 117 °C while the GPU temperature was only around 60 °C.
I initially re-mounted the block, but the temperatures remained essentially unchanged. I eventually replaced the front-side thermal pads with thermal putty, which fixed the issue.
However, there is an interesting detail that I wonder if you have considered: the spacers in the centre of the block, the ones that look like hexagonal nuts, seemed to have become loose. I tightened them before reassembling the block.
Could these spacers be losing preload or backing off slightly over time, perhaps as a result of thermal cycling, perhaps when handling the block or assembling it? If their height determines the final mounting pressure on the GPU die, even a small change could potentially result in insufficient or uneven contact pressure.
In my case, the combination of redoing the thermal interface and tightening those spacers brought the hotspot down from ~117 °C to the 60–70 °C range, with the GPU temperature around 64 °C.
I cannot say which of the two changes was responsible, but the fact that those spacers were loose made me wonder whether this could be a contributing factor worth investigating.
