Magic Trashman has written a tutorial on how to padhack a Neo Geo Mini controller to DB15 (arcade/Neo Geo direct connection) and add a clicky microswitch d-pad to it. It’s a relatively complex mod involving custom 3D prints, but MT has been offering pre-modified controllers for sale through Twitter.
I bought one of these from MT’s first batch and I was surprised at how solid the new controllers are. I own several of the original Neo Geo controllers and the new modified one by MT is actually my preference.
Photo Tutorial: https://imgur.com/a/ilmSDPK