I have a USB T7 SSD drive of 1 Tb with a 600 Gib rolling size… is this too much?
I would say, YES, that’s way too big.
Yeah on a USB port that sounds pretty terrible.
You would do far better if you could have all your MSFS stuff and OS, M.2 devices.
SATA SSDs have a maximum speed of 600 MB per second, while M. 2 PCIe cards can hit 4 GB per second.
A USB thumb drive is more like 60MB/s !!!
If you MB does not support M,2, an inexpensive M,2 PCI card that can hold 2-4 M,2 drives is a viable choice.