From TFA
> VMware to Proxmox migrations are not affected ...
Amusingly - and acknowledging tiny scale and modest automation requirements of home lab compared to enterprise - as I started migrating to Proxmox a year or two ago, the process of shuffling VMs off my ESXi servers and onto Proxmox was surprisingly painless. Effectively mount the ESXi as storage systems, and then 'copy to here'.
IIRC the only small challenges were a conservative choice on target VM's CPU type (Proxmox seems to dislike defaulting to 'host' CPU) and the network / SCSI controller defaults. I assume designed to prioritise robustness over performance.
All automatable, I'm sure.