When used with the full py suite (including the new alternative energy mod), automatic train painter appears to change the Automated rail automation technology from depending on the Railways 1 tech to depending on the Railways 2 tech.
For example, with the save linked below, the above occurs, if only Automatic train painter is disabled, automatic rail automation returns to depending on the Railways 1 tech.
Save: https://drive.google.com/file/d/1Mp1lmBz2IOwTpFrblRldFhDnzFtw6p2o/view?usp=sharing