Moonie,it will take a lot of heat to do any damage. considering the amount of heat typically used on hoses to get them pliable, I doubt you will do any damage heating up the hole after vacuuming.
Interesting choice of tool for a professional surveyor.. Did I read it right that he did not have his own moisture meter and you used yours? Most would use a small brass or phenolic/plastic hammer but if that is what he is used to than I'm sure it could work for him..I have no way of knowing if the leak was prolonged or not, I have had the boat for a week tomorrow. Surveyor and my own moisture reader findings indicate that the decks are dry, still have that nice sharp ring when sounded with a screw driver handle. The holes were only exposed for a day or two, we had light misty drizzle.. but again, I stress... as far as I know, the decks are dry. Today we had a train of torrential rainfall come through Charleston, I did a quick (effectiveness remains to be seen) cover job with a slew of duck tape.
The manufacturer glassed over fittings from below so that deck leaks will not make themselves known.