For some reason, distributed's opencl ati tasks causes my gpu to only reach about 60-67*
°C, but the hotspot reaches 105-110°C, which i believe is causing my sudden system shutdowns. Yet other games, stresstests, and even other projects don't do this, and the hotspot only reaches 80-87°C with core temps 65°C and the system remains powerd on and the gpu util is maxxed out.

If you have a Windows driver you could try automatic 'GPU undervolting' in your Performance => Tuning tab.
It could help to drop down the card consumption and also your hotspot temperature with no performance drop.

Also, you can create a custom 'gaming profile' for this app and set the 'Power Consumption' limiter for this app.

But on mine, Radeon VII with a basic TDP (maximum consumption) of 250W, is when computing this app the GPU hotspot also much more higher than the GPU temperature and in my case it was about +35C difference.

However, after I replaced the heatsink which was too small compared to nowadays graphic cards with something bigger it is no longer hitting 105C. Despite that I have not had any problems related to too high GPU hotspot in the past and this card was running for months like that.

yeah this program is the only one I've seen that brings my hotspot up to 100, everything else (gaming, other BOINC applications, Furmark, etc) max out at around 90 - I'm assuming that's because it has more efficient utilization of the GPU when compared to those other tasks? not really sure

I'm assuming that's because it has more efficient utilization of the GPU when compared to those other tasks?

it is more likely this reason and also it is a large chip

After some time, the issue ended up persisting with other applications and ended up being an issue with my GPU, it was still under warranty so I'm getting it RMA'd with Sapphire. I'll test it when it comes back to see if it's resolved. For under-volting, I had to under-volt it way too much to get it to not overheat on the hot spot and it was unstable.

rma replaced the gpu and its all good now. no more overheating