I am not sure your issue is quite the same. I don’t get bugsplats or not responding. What I get is immediate crashes which bypass the whole bugsplat reporting procedure. Sometimes it is just LO that crashes but sometimes it crashes the whole computer. It seems to be random (some files affected but not others) but the source of the crash is always the same - changing rendering from the default raster to hybrid or vector.
I did try what you suggested about saving in 2017 format and opening in LO 2017 but the same thing happened. So it must be something about the way LO handles files leaving an inbuilt problem. My only totally failsafe option is to revert to SU and LO 2017 altogether. I really hope I don’t have to do that!
I am surprised that I am (so far) the only one with this very specific issue as there must be a lot of people out there running 2018 on a Mac just like mine.