Rather than working as an analog command, /throttle now seems to just set the throttle to the maximum. There seems to be no difference in calling /throttle with any number between -1000 and 1000.

I had Mecha test this out for me as well, he said it was the same on his machine.

(I'm running the Linux/AMD64 client, Mecha has the Windows client)

Does it work fine when bound to a joystick axis?

Yeah, it works fine then. I'm trying to set up a few aliases using it though.