Does it require an update or is it still usable?

Oh right, thank you for the quick answer.

In CK3 armies can cross major rivers only at few select places. While in CK2 armies could cross from one bank of a major river to the other at basically any point that they wanted.

I don't understand what this mod does?

Armies taking ages to cross rivers was the only thing holding me back from using "More navigable rivers".

Thank you very much for creating and sharing this mod. Thumbed up.