Also, even if this would work, this defeats the purpose of the "hot" conversion.

I am having the same exact issue, with the same scenario. Attempting to perform live conversion from VMware to Hyper-V. When I go to power up the migrated VM on the Hyper-V host, I get the Windows BSOD stating "Inaccessible Boot Device". Once I turned off the VM I can no longer get into th...