I enjoy the concept of this mod a lot. There are some things though that I would love to see added.

• Rotating blueprints - Depending on the rotation of the train in the blueprint, it can spawn backwards in the Train Foundry. It would be nice to just have a option to be able to flip the blueprint so I don't have to manually do it before adding it to the foundry's library.
• Generic fuels - The generic fuel option automatically lists the three best available fuels which is almost always fine for vanilla, but with certain sets of mods those top three fuels aren't always desirable. There should be some way to either set a preferred generic fuel, or to blacklist certain fuels so they don't show up in the top three.
• Circuit connections - It would be useful if the circuit connector could send out 'requests' on one color of wire and 'storage' on the other color (this is a new feature in 2.1 for other circuit enabled buildings).
• In the Smart Train Combinator version of the mod, there is no way to spawn a train with an unusual locomotive placement (such as common double headed trains, or my preferred style of having the locomotive push from the back). There's also no way to specify to use modded locomotives (like from Better Train System or Electric Trains).

hello,
thanks for the feedback
- rotating is very hard, so much case... i prefer to stay like that, it would be a source of bug
- generic fuels : yes, i'm fixing bug about quality and yes i think an ui like you say should be important, like exclude eggs
- circuit connections : yes in my mind, and in the next version
- smart trian combinator version: i think about it too yes.

two of your suggest are publish ;)