You can't really expect someone to just become a badass and make a 180° personality wise, this is why i don't understand the "Usopp reverts to a coward every arc" argument, he's a coward but he's also pretty brave because he manages to overcome his fear when it matters the most and does get his badass moments.

One thing that could happen in Elbaf is the trope where he realizes that he's been a brave warrior for a while now like he wanted to be which gives a new point of view and is close enough to the instantly brave and badass Usopp people seem to want.

I don't know, i like the cowardice because it showcases the bravery more, there are many other badasses already that are pretty cool.