At present the mod builds locos/wagons from fully built Yuoki wagons and locos, which means that, if you are using more than one type, you have to build a Yuoki workshop AND a Trainbuilder for each wagon/loco type.

It would simplify things a lot if the Trainbuilder could build Yuoki trains from the components used to make them, which would simply require Yuoki Train Material Factories for the components and a Trainbuilder for each wagon/loco you are using.

Works as intended, the yuoki workshop makes the big parts from the components and the trainbuilder does the final assembly, otherwise there is not much use for the workshop anyway?

Yes but the "big parts" is the whole loco/wagon - if you are using a range of them - that makes for 2 assemblers for each type - the Yuoki Workshop and your Trainbuilder - if the Trainbuilder can't make from the components it's far simpler to just use the Yuoki Workshop and copy/paste the trains don't you think?? BTW there's 43 full length wagon types and 23 full length locos (not including the tenders) if you have all the Yuoki Rail mods installed. That's a lot of Yuoki Workshops and Train builders!

I'll see if I maybe can make a setting for that so you can toggle that behaviour... I'll put it on my todo list (which is quite long atm...)