> I would recommend letting some chlorinated water run through and sit in softener before bypassing.
I'm told that bleach is harmful to the resin bed. So I wait until most of the chlorine is out of the well water before running it through the softener.
We had an old Sears water softener that was on its last legs the first time I shocked our well. The bypass valve was broken, so I ran the full strength solution through the softener. It never worked well after that, and I suspect the bleach is what finished it off.