Yeah. It's a certain amount of work, but it should be straightforward to make adjacent routers connect/disconnect/reconnect automatically based on their belts. I sort of already have special poles (implemented here as lamps): I can just set them to have very long connection distances and hidden wires.
The main issue is when to run the connection detector, or whether there is a manual process. If it's manual, then this might it harder to blueprint routers. If it runs on every belt placement/removal/rotation then it will cost a lot of UPS. So it requires some care. If there were a really lightweight way to do it, then taking LTN's approach and scanning a few times per second would work, but I can't scan every belt in the base every few seconds.
One possibility is to make a variant of each belt and underground type, only for sushi routing purposes, that looks slightly different. For the sushi network you would then use these special belts, and maybe you could convert them to/from regular belts. Then I would only have to check connectivity when those belts are placed/remove/rotated. This feels like a bit of a kludge though, and I haven't spent the time to implement it.
It would be an inventory management hassle to have "express belt", "express underground", "sushi express belt" and "sushi express underground" in the mall though, even if it was free to convert between the regular and sushi versions. But maybe there's a solution where the sushi version exists only as an entity (not as an item) and the mod converts on the fly to avoid re-tracing the belt lines every time.
