Eager zero seems to do nothing
When creating a host it is possible to select 'Eager zero' for the VMWare VM.
But if I check this option, the VirtualDisk is still marked as 'Lazy Zero' in VMWare.
Also, when creating a new VM from an existing Image/Template, the resulting VM's VirtualDisk also always is 'Lazy Zero'.
Looks like there was a fix recently, which solved a related issue for Thick/Thin-Provisioning: #27015