Not surprising, it takes extra work to make script-based locomotives work with ither mods. You can continue using them together by adding those locomotives to the MUTC blacklist setting.
If the code works, it looks like there is an interface in RPS to register new locomotive and rail types as electric. If RPS updates to Factorio 2.0 I will definitely take a look at this. It's unlikely that I will publish any more releases for 1.1.
