Nudge script have an issue:
01. invoke bevel.
02. use Tab key to change gui focus from "Radius" to "Shape".
03. use RMB or Enter to apply bevel
04. Select object and try to use Up & Down Nudge commands.

Up and Down Nudge doesn't work after this. Until you press Tab key and then Enter.
It happens i guess because gui focus stak somwere on already closed bevel "Shape" gui.
Its interesting that Lef and Right Nudge still works.

It's not a huge problem at all but kinda annoying.