The Standard is based on the Yamaha Pacifica models. A Pacifica neck will fit on the Standard, but since they are basically the same neck that doesn’t solve the problem if you don’t like the neck’s feel.
A Fender neck won’t work on the Standard body. The scale length is the biggest issue, but they also have different neck screw spacing/neck plate sizes.
No one makes replacement Variax Standard/Pacifica necks. I looked into it while researching the lefty transplants I’m building for myself and a few lefty customers.
Your best bet at this time is to have someone dress the frets and the fret ends, and set up the guitar to get a more pro feel out of the neck and guitar in general. You’d be amazed at what a difference this can make.