Sorry to hear about your problems during your vacation.
Can you take pictures and use other commands with the mobile app and it’s only the plug-ins can cause it to crash?
I just tested my Google Pixel 2 to make sure that the RICOH THETA mobile app still works in general.
If it’s crashing only when you try and retrieve the plug-in information from the camera, but works otherwise, there may be configuration information that got corrupted. (I’m guessing). If that’s the case, deleting the plug-in configuration might work. (guess) Unfortunately, this would be a hassle as you just have a mobile phone would delete all the plug-ins and configuration settings.
If you have a friend that has an iPhone, you can check to see if the THETA iPhone app is crashing.
@iantresman just posted a link to a mobile app that can send API commands.
Hope you manage to have a good vacation despite the technical frustration.