Welcome to the board.
If you have a question about Hutch or old school BMX,
feel free to post them here!
my hutch has two small holes inline with the rear dopout slots and they have small allen bolts in them they look like some kind of chain tension supports but they look very factory
Yeah those were made for a chain tensioner.
Such chain tensioner is little plate with tooth in the form of a 6.
they were called whale tails, I think.