Just updated from 1.1 to 2.0 and downloaded this mod as my original AFH for Py mod didn't migrate to 2.0 but many of my underground connections broke as they were short by 1 tile (Niobium undergrounds).
The +1 tile setting is only being applied to Iron (T1) undergrounds, whereas my previous mod applied the +1 tile by default to all three tiers, including Niobium. Which makes sense as the +1 is to replace the tile of the pipe no longer being placed as 1 tile has replaced 2.
I edited the mod to add the +1 distance line from T1 to T2 and T3 too, which fixed my T2s. Could I suggest that gets done by default for the +1 setting option to apply to all 3?