(imported comment written by BenKus)
We actually used to do it the way you suggest, but we got a lot of complaints that admins and the operators were accidentally upgrading to the wrong versions because they picked the wrong Fixlets and they would be very unhappy when they would have to re-upgrade again. Additionally, many companies will globally hide upgrade Fixlets and if we add new Fixlets, they sometimes would forget to re-hide them and that can cause issues too.
So we moved to the the method of updating the upgrade Fixlet when we do a new build release (i.e., 7.0.7->7.0.9) and then publish the older Fixlets for those who need them.
It seems like the requirements conflict somewhat in this case and we can’t find a way to make everyone happy, but hopefully for companies like you that need access to the older Fixlets (for internal process or external regulation rules), importing the older Fixlets can be just a minor annoyance.
We will address the issues you raised regarding the archived Fixlets. Thanks for noting that.