I don't find it surprising that the VRM's on X299 are struggling.
Intel designed this range of CPU's with a quoted TDP of 140W.
In tests, the i9 ten core has been found to be pulling 300W when overclocked, so it's hardly surprising that some VRM's are getting hot.
Because this platform was rushed out, the board manufacturers are still using immature BIOS which get the CPU stable are likely using voltage settings that are higher than they need to be, and thus causing the CPU to draw much more power.
Once they learn how to control this new range of CPU's with lower voltages, and thus draw less power. I'd expect the load on the VRM's to be reduced considerably. So it's quite likely that more mature BIOS will fix VRM issues.
One thing I will say, and someone very close to me predicted this a while ago.
And to quote him "The core wars will only end in tears for consumers who automatically think that more cores are better".