Would it be possible to ignore some signals with a selection tool? For example, this is useful for depot signals that stack more than one train at a depot stop: https://i.imgur.com/YCptPEI.png

Would very much like to do that. Problem is, figuring out which signal a train is stopped at is difficult and somewhat unreliable. I've submitted a modding interface request. If Wube decides to implement it, this is going to happen. Otherwise, probably not.

0.4.2 has a selection tool to ignore stations. Bilka has added my request to the next version of Factorio. Once 0.17.33 goes live I will update the selection tool to work with both signals and stations.

Edit: Signals can now be ignored. Requires Factorio 0.17.33.

\o/