Hi Shanreich,
It's the issue was a mixure of two issues, the cards and the Mikrotik Switches.
On Proxmox I have to do add a postup for the vlan offload, otherwise I've found sometimes the VLANs on a bridge don't work at all, it's not very...
Did you create a enhancement request?
I commented on one but just realised it was for OVA, not the ESXi guest importer
https://bugzilla.proxmox.com/show_bug.cgi?id=6113
Not having a pool option also means you need someone with full permissions...