Hey, congratulations!
Are you only looking @ USB sticks? Others have used SSD/NVMEs in external enclosures successfully… but to your question:
We have word from GL the Beryl AX is:
… so I would look for a stick w/ a minimum of 80 MB/s write. Most are advertised in read. Eg: Samsung’s FIT Plus USB 3.1, 256GB is advertised 400 MB/s read, 110 write. I’ve hit 116MB/s write on it my Flint (GL AX1800). Testing gives 412.13 R, 116.97 MB/s W (SEQ1M/8QT1) using CrystalDisk 8.04 x64.
Meanwhile my Samsung BAR Plus USB 3.1, 128GB hits 411.31 R, 64.80 MB/s W in SEQ1M/8QT1 (CrystalDisk 8.04 x64).
So there’s a bit of a difference. Basically any brand name drive/stick would work but I personally use Samsung & Kingston. Don’t forget you have a microSD slot too.