Expand VxRail/VCF Cluster - Create new WLD using non-VxRail ESXi nodes

I searched but could not find any topics related to this scenario - would this be a supported configuration with both Dell and VMware? 

Adding non-VxRail ESXi nodes (Dell R740's & Supermicro servers) to an existing WLD? 

Or creating a new WLD using non-VxRail ESXi nodes?  

What would be the ramifications in doing so?  I know that VxRail Manager & SDDC Manager (for VxRail) would not be aware of these external nodes (and thus would not be able to manage them, etc), but indication we got is that it may be supported configuration? 

Thanks!