Have you ever made any kind of modification to Ultimate backup regions?
If yes, see if you can edit the vehicle that is going to spawn by United Callout or edit Ultimate backup regions. As UB is blocking United Callout to spawn that vehicle
For this one, playing around 30 minutes is expected.
And this one, since albo1125 has decided not to update his plugin anymore, just use other callouts
Is that only when you respond to assorted callouts' call, the game experience crash. Or when you reach somewhere in the game, the game experience crash?
Crash after playing 30 to 40 minutes is expected. Its already doing well in most cases. However, maybe you can try not using stuff that is outdated, it might extend your time of not experiencing crashes.
It works everywhere, even people living in mainland china works, so living in Australia shouldn't be a reason why it doesn't work. When you open Ragepluginhook, is there any warning message saying that something hasn't been installed.
Try to spawn that police vehicle. If you failed to spawn it, that should be where the problem comes.
BTW, did you install Ultimate backup and make some changes to regions?
Doesn't need to change the mods folder to _mods if you found that the problem isn't from GTA5.
Have you ever tried to reinstall ragepluginhook and lspdfr