Regarding overheating: Since class 0 AVS isn't implemented yet (afaik?), it may be worth checking how the core/mpu/mm voltages that are used compare to those specified by efuse on the individual boards. Voltages high enough to allow weak-process dies to run stably cause excessive current and therefore heat on strong-process dies.
The efuse-specified voltages (in mV) can be found in the lower 12 bits of the following registers: