My biggest concern is how the setup will respond with Clutter and Turf-FX. I recently "discovered" how much better it makes a route and I'm hoping that this can be enjoyed at a reasonable fps without the jittery gameplay. The problem is that, when the game jitters, the consists in motion on the route jerk forward a few hundred feet and tend to derail a few cars. I'll go from filming a Manifest with 5 motors on the head end to filming it again with 2 of the motors gone and the actual cargo following a couple hundred feet behind the remaining power. Definitely an interesting sight lol
I have no issues with Clutter and Turf-FX causing stutters. I don't use the PBR textures due to other reasons not related to graphics and that does help with the cooling, though. There is one thing that should clear up your micro stuttering. Disable G-sync. This issue isn't inherent in Trainz, and there are complaints about that with other games as well. I also run at half-sync (30 fps). It may seem counter-intuitive but with all kinds of assets with different levels of quality and LOD, along with the constant loading of data, there's no noticeable difference.
As someone from the US, I'll run prototypical freights on my very long routes that are about 7200 feet long or longer without issues. There is an odd bug that will sometimes, and I mean intermittently, cause a long train derail, due to a switch being flipped under long freight cars. That issue has been with us as far back as I can remember and I've used Trainz since TRS2004 came out in December 2003. Like many things, this is something that comes with many theories as to why it occurs when someone asks about it in the forums.
There are a couple of things totally unrelated to this that can cause your derailments, however. If a train sent from a portal with junction too close to the portal and set against the route, the train can derail, or split apart as you've experienced. When an AI train is sent from a portal, it's blind to the world and gains its driver and commands once the whole train is out of the portal. This is true even if an absolute signal is placed before the junction since there is no driver even if there's one in the driver's seat when we click on the train.
Another issue that has caused derailments is the Small Portal Basic, or however it's named. There was an issue with TRS22 after an update that caused all portals to derail trains. N3V fixed the issue and we tested and tested, but apparently the Small Portal Basic still has that problem. Switching to the larger portal basic solves that problem.
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