Hi, I replaced the thermal pad (which is a solid pad with low thermal transfer, I would say about 3W/m.k at most) having made measurements beforehand and I obtained a measurement of about 1.5mm thick, so I replaced the original thermal pad with a thermal pad cut to the same size from Thermalright Valor Odin which has a heat transfer capacity of 15W/m.k, which is significantly more important but I use still the original VRM heatsink so the gains are not crazy either, according to the probe plated on the VRM heatsink the temperature would have dropped by about 10°C, after that I now use an IDCooling IS-50X(v2) which allows a large airflow to be blown on the VRM heatsink, which in my opinion helps a lot in this 10°C drop.
Regarding the specifications of the VRMs, all I can tell you for sure (but sorry I no longer have the links reporting all the information, but it should be possible to find it by searching carefully via Google) is that it There are 5 VRM phases of 50A and these phases are configured in 4+1, i.e. 4 phases dedicated to the CPU cores and 1 phase dedicated to the APU's InfinityFabric therefore dedicated to the iGPU part, memory controller, PCIexpress lines, the management of SATAs and USBs, etc. Sorry for not being able to tell you more, but hope this helps.