Thank you for your reply. I did remove the rubbers thanks for the reminder, I thought I made a mistake before by removing them 🙂 (And don't know what they actually do, I guess for packaging reasons)
So undervolting is not a bad thing, and from the get-go this is an issue with G752 so I think I'll continue on undervolting.
I do want to increase the multiplier of all cores to x36 (It's x36 x34 x33 x32 for cores 1-4 respectively on default) but kinda afraid since I didn't do any OC before.