It does not appear that SMART is supported on either version of my TerraMaster enclosures.

Still an inexpensive solution to help ease your transition away from MacPro"5,1"land.

As USB-C is a physical form factor (capable of supporting multiple protocols), I would think that the ability to have multidrive external SMART support would be up to the vendor's choice of datachip/datastream. Again: my Acasis does support SMART for nVMEs.