TS-473A QTS TPU adding Drive Caching on QM2-2P-244A/QM2-2P-344A expansion cards

For anyone who cares,
Put in a QM2-2P-344A and simply moved the PCIe SSD from a system board slot to the Gen3x4 M.2 card and it launched - Much improved

Moral of this story is DO NOT ASSUME that the M.2 is high speed. For the TS-473At, it’s a PCIE Gen3x1 which is the same performance as a PCIe Gen1x4

I would assume that Cache is a similar issue - without all four channels, the Caching would be pretty lame.
T