To keep expanding the thread there are many more items to think about. What is the terrain like? Lots of ways this can play out depending upon the sounding but there is no way to determine the thickness of the cloud layer. Might set up a perfectly good, stable, and safe descent only to fly it right into the ground. The spiral might allow drifting back into the downward side of the wave and the descent rate will go way up; be prepared for strange instrument readings. The pilot won't know how they will react to unusual and frightening operations. Most people don't fly much wave and make a trip to grab a diamond and tend to go since they just have this weekend of camp to make it.

In general, the OP scenario can be avoided by checking the soundings for the predicted wx during the flight. I know, the forecast can be wrong but taking a look and preparing for the potential can't hurt either. If the trend is the DP and temp getting closer as the day goes on the chance of getting closed in go up. The scenario an be avoided by seeing what the local pilots might do as local knowledge is very valuable. If the wx looks iffy, stay on the ground or change the flight plan. No flight ever has to be made.