So say, I have 2 trains that take up 2 tiles, and the platforms of the station are 4 tiles long. If I was to use permissive signals, would it be possible to have them share 1 platform, and load and unload passengers all at once?
I doubt this would work reliably if both trains are heading the same direction. It's hard to control where exactly a train stops on a platform, even if you've specified in the schedule.
If the trains are terminating from opposite directions, then you can disconnect the rails between the two halves of the platform so that they don't interfere with each other.
I ment for the case when both trains are heading the same direction. I haven't tried this myself though, but will soon.