Sorry for my noisy posting yesterday, my eagerness got ahead of me and I did some bad testing. Right after I made my last post I crashed yesterday after I had completed several touch and gos, which had not happened before, so I started testing everything a bit longer to see what would happen.
After a few slightly more involved tests, I am starting to become convinced again that it might be the 3jFPS FlyWithLua script after all. I was doing kind of a binary search with enabling plugins yesterday to quickly narrow it down, and I was pretty sure it was either autogate, the simtoolkitpro plugin, or the 3jFPS lua script. I deleted these one by one, got crashes the first two times, and then after deleting the lua script I was able to do 5 or 6 touch and gos and was in XPlane far longer than I had been prior to that. I re-added just the script and crashed pretty quickly again. I'm not sure this is enough to go on since the logs aren't providing a ton of details, and I obviously want to spend a bit more time with the plugin disabled to make sure it just isn't coincidental, but it seems like it might be the culprit