I said:
It does not work on the computer where I am sitting
.. But actually it does work, i.e. X clients on that display no longer receive key repeats after an xset -r is issued on any session whose DISPLAY is the X server that I am looking at here. The PuTTy terminal window is not a X client so it's keyboard events are coming from somewhere else.
It seems to work for PD runnign on the Linux machine while I am logged in, in this way (looking at the behaviour of the right-click 'help' from the 'key' object found in lib/pd/doc/5.reference) and also 'keybin-help.pd' posted to the list. It's a property of the 'display', not the machine or the shell session, however.
I think you could not easily have another program running in which key repeates ARE active; unless it's on another display; also if the program bypasses the X and gets its keystrokes from the kernel directly, probably it would not work as expected.