When I enter into a claim with a train (I specifically used a handcar from C.: Steam 'n' Rails) I get a ton of error of why I'm interacting with this entity, then it gets stuck on the other player's claim. I think it should make an exception if you own the train

the game doesn't seem to properly recognize that the train belongs to the player, leading to the train getting stuck in the claim area.

solution might be to add a check in the code that verifies whether the train belongs to the player before triggering any claim-related logic. This way, the game would recognize the train as the player's property and allow it to pass through without causing errors.

Trains don't have owners. Avoid situations like this.

run the /create trains command, they have owners

Interesting! I just assumed they didn't because that is the case with every other type of contraption. I guess something could be improved here then.