Finer details about highest performance for video editing

[Enquiries]

Hello, I've already purchased everything, DS1621+, six WD RED PRO 14TB, two 10gb switches, and two WD BLACK SN850X NVME SSD. I'm aware that the SN850X are too much, the NAS can't do PCIe 4.0, I wasted money on un-used performance. My question today is, I bought two SN850X 2TB, but it seems nobody else is doing that. Everyone else is doing 1TB or less. Should I use 1TB NVMe instead? Is 2TB NVMe too big? Did I also waste my money on too much NVMe SSD?