Thank you for the reply, Greenglofer15. I have uploaded log.txt files and crash reports to LR, but they have no suggestions (the crashes were too random), and I had forgotten that Flyinside is no longer supported. However, I think I have sorted it all out. I posted the following in X Plane forum last night:
With the Samsung Odyssey headset the order of operations is as follows:
1) Start up the headset, then Steam VR, set up your aircraft, enable VR in X Plane 11 and go fly.
2) If you disengage VR in midflight, after 10 minutes the headset goes to sleep and Steam VR completely switches off and the sound returns to the computer. If you choose to re-enter VR during the flight, you must do the following: wake up the headset, start up Steam VR again and THEN enable VR in X Plane 11.
So far, I have had no problems moving in and out of VR using this method. I hope this helps someone else out. :)