2. Stopping Behaviour
Regardless of the 'Platform Type' setting, trains will always stop with the centre of the train aligned with the centre of the platform unless the 'Configuration' option is set to 'Terminal'. The centre stopping point is marked by the platform number indicator.
If your platform length is 200 metres and the configuration is 'Through' the script will search 100 metres each side of the centre for cars with doors to open.
When you set configuration to 'Terminal' the search zone is calculated differently. The search will usually be 50 metres forwards and 150 metres backwards. The train will then stop (roughly) where the passenger zone ends but the total search length will be the same. Any increase in length will be added to the backward part of the search, the forward zone will never change.
The 50 metre forward zone is defined by two tags in the extensions table in config.txt, terminal-cars is the number of carriages which will be allowed to pass the sign before the train is stopped and terminal-offset is the length of the 'forward zone. Alter these values if you wish, but at your own risk.
If the length of your train is equal to or less than the terminal-cars value the train will stop short of the buffers. This is to ensure that part of the train stops in the trigger zone, the script can't detect the train otherwise.