In case anyone ever needs it, I'm pretty sure I've corrected that annoying and many-years-old problem with the Oregon Scientific WMR200 driver. It seemed like the device itself had a firmware issue where it would rarely and unpredictably stall. The previous driver didn't handle this at all and just exited...
I added a short handler to catch when such a stall occurs, and retry up to three times, resetting the port before each attempt. So far, it's working here - having caught one such stall after about a week, resetting, and on the first attempt, recovering normally.
If I notice any other issues that pop up or that I can fix, I'll keep that repo updated.
-John