The P360 Ultra has an additional Pcie 3.0 x8 slot aside from the Pcie 4.0 x16 occupied by discreeet graphics.
With that slot I bought a QNAP QM2-2P10G1TB. A 1 x 10GbE with 2 x M.2 NVMe 2280 expansion card. For network and addtional storage. As the above poster now I have 4 x M.2 ( x2 on board...