i have both graphics card from XFX with chip rx 6600 and rx 6600 xt,and strange thing is both GPU have temp of chip 60degrees but 6600 have normal hospot 72degrees but 6600 xt have 85degrees,dont know why,i see many reviews where have infra camera and dont see this hot spot on card,but this high hot spot is only on rx 6600 xt why not on 6600 ?
Then you should contact XFX tech support for them to explain the difference, AMD supplies basic chip/board to aftermarket makers who then may make additions/alterations to the base specifications as well as using different component models (usually within AMD spec.) such as caps/mosfets/pwm/etc......, also some make/models have their own better cooling.
This is why you see different makes/models with varying specs/performance in benchmarks etc..........
Hotspot temp is the hottest part of the gpu die,so the difference is from aplication paste,base of the gpu cooler,a bit higher tdp.
At 85C hotspot is ok,after 100C i will be worried and think to replace paste etc.
Even with watercooled gpu hotspot is hard to keep bellow 70C.