>>106015953It results in an overshoot of voltage actually
If a board reports to the CPU that the power plane resistance is something like 1.1mohm but the ACTUAL plane is 0.540ohm, you get an overshoot because the CPU is requesting a voltage from the VRM expecting a loss from the actual electrical resistance of the vcore plane that actually isn't there.
If you did the opposite like set a 0.540mohm LLC on a crappy board that has a 1.1mohm vcore plane then you would get a lower voltage to the CPU then what it expects.
On my Asrock taichi board specifically, they had two separately released options going into the 13th, 14th gen fixes.
"Baseline" set LLC to 1.1mohm, this resulted in 1.45v VIDs with something like 1.42v on the external Vcore sensor.
"BIOS default" set 0.540mohm, this resulted in ~1.425v VIDs and the core sensor being ~1.4v which is exactly the voltage the CPU wants at 6ghz