You can use adb commands to "disable" system apps FWIW, all you need is the "developer options" menu, to temporarily enable adb access from USB. This lets you use all the features of a "locked", stock "ROM" (payment services, DRM apps, better camera), and also works on "locked down" devices where you can't unlock the bootloader and install a different OS. Of course, it's only worthwhile if you trust the "ROM" vendor (LG in your case) and can isolate the problem to some specific app(s).