Just to clarify upfront, I’m not missing an option for prioritizing and/or selecting what each resource importer can bring in right? Want to make sure I’m not missing an existing feature. I think your point is that you’d only hook certain resource importers up to certain production slots and this is harder to do currently since they auto-join.
The more customization in layout a game like this has, the better IMHO. It makes tweaking and trying new designs and complication (or simplicity) that much more fun and keeps you playing. Therefore, I’d support this change.
I’ll flag my post here while we’re discussing this though. If you going to force the player to design junctions, I think you should take into account when the player is charged funds.