Now I know the proper name of the katana grip pattern. It inspired me to do some youtubing. Learning new things everyday!
The only advice I have regarding the wrap pattern is that the criss-cross feels a bit too flat in your model. Like it’s losing volume, especially when seeing the handle as a whole. I think there’s room to make the criss-cross protrude out a bit more. This photo for example:

As for bending the arrayed pattern, a lattice is a great choice. Also a Simple Deform modifier set to “bend” would do the trick too.
And I 100% agree with @silentheart00 that a voronoi procedural texture would be great for the underlying handle.
It’s so cool to see your process for creating the shape. This thread can now serve as a worklog for others to learn from. Way to go, Thibault.