This Brio compatible train stop block has a threshold to the stop e.g. the „BRIO World 33214 Batterie-Frachtlok“. It might be compatible to others but I just tested this one. This locomotive has a little sensor on the bottom side that is triggered by the threshold on this stop block. So the train will automatically stop before the stop block.

I printed it in PLA using two walls and 15 % of infill.