Workstation 15 permits the hot-adding of a NIC.  What fixed the issue was the following link that provided entries in the VMX file:

https://community.netapp.com/t5/Simulator-Discussions/issues-about-Simulator-Clustered-ONTAP-8-2-1RC...

pciBridge0.present = "TRUE"
pciBridge4.present = "TRUE"
pciBridge4.virtualDev = "pcieRootPort"
pciBridge4.functions = "8"
pciBridge5.present = "TRUE"
pciBridge5.virtualDev = "pcieRootPort"
pciBridge5.functions = "8"
pciBridge6.present = "TRUE"
pciBridge6.virtualDev = "pcieRootPort"
pciBridge6.functions = "8"
pciBridge7.present = "TRUE"
pciBridge7.virtualDev = "pcieRootPort"
pciBridge7.functions = "8"

I had to convert from EFI to MBR because at work we will be converting an ESXi cluster running on hyperconverged Nutanix hardware to running natively on the Nutanix hypervisor.  For the conversion to be successful with every VM (and we have a few hundred,) any VM machine that boots  from a UEFI partition must be changed to boot through a MBR.  We only have about 15 VMs that are affected but we needed to come up with a way to convert them without losing any data.