Yes, you can use "go nodes 1".I took the fast TC because I am really interested in what happens at very low node counts. I heard stories that a one-node Leela is rated over 2000 on some server, (playing against humans, no doubt), and I want to see that before I believe it. Does it support "go nodes"?
However, the net you've got (assuming you've stuck with the one provided) is rather weak (and is provided because it's small). If you want to play 1-node at strength, I'd suggest the SV-3010 net (which was used at TCEC) which you can find here:
https://www.comp.nus.edu.sg/~sergio-v/t60/384x30/
I've seen it beat a > 2650 GM at 1 node (admittedly at blitz time controls) though he may have been giving it too much respect. Using CPU only, I (with a mid-range CPU) get only 1 node per second for this net though; as opposed to 5000 or so on GPU.

