It would have been nice to get a result, but it became a bit of a PITA, remembering to login to the Fedora box and kick off the script every time the router restarted, eg after a power cut, which are common around here.
The other trick that I suspect might fool DLM is to leave the router synced at a very low rate, so that error rates really are very low. Mine retrained in a thunderstorm just last night, at about 800kbps below normal. I'll leave it that way for a few weeks, who knows, it may do the trick. But I shan't claim it as a success for my cunning plan
