Is it possible, that the code of this mod gives me 'long reach' not only for waterfill but for all constructions? I just recently realised that I can place stuff like belts as far as I can see (max zoomed out).
I would consider this a bug, if it was the case.

Or let's put it another way. I think your mod is responsible for my construction range being stuck on a high value.

The mod itself should not cause your issue. However there is a possibility that another mod has code that interferes with my modifications of reach distance.

Does this also happen on a new map without you touching any waterfill?