hello, just want to add that this happens on Nauvis too (at least to me). It seems that if roads are separated by f.e. rails, they teleport and instantly deliver what is requested, they also receive steam instantly from the depot. with an uninterrupted road, not blocked by anything, they drive back and forth as intended.
IIRC in 1.1 the drones did not care about any other object besides hitboxes of buildings; rails, trains, belts, etc. were simply ignored, they only needed an uniterrupted road below them.
thank you very much for working on this wonderful mod :)