I noticed that when I drive the Flirt 1 over the switch right before the main loop, it just, bounces, derails. A solution would be to smoothen the path which goes from inside to the loop, so trains like this won't suddenly get hit into the tilting track immediately, idk
I think there's a simpler solution: have a look at the level crossing at the top of the loop. This section is already flat. All they need to do is complete the junction to allow going onto the loop from the track going north.
aw man yeah. that crossing was the one I wanted to drive on, but couldn't, because the switches won't f-ing move