Adaptall was just a system made up by Tamron for their old manual lenses that belonged to the system. It is like an adapter ring for the Tamron proprietary mount to the camera mounts in question. Try to google for Adaptall and you should see the thing in action. There are no elements in it and therefore cannot affect the factors you mentioned.
Only Tamron Adaptall lenses can use it, and only they need it. You can't fit the lens to a camera body without the adapter.
I believe Tamron had earlier versions, but the one I remember (from the 80s) is the Adaptall-2 system.
Rather than make custom fit lenses for all the different SLR mounts available then (there were MANY!), Tamron made one lens mount that fit onto the Adaptall-2 adapter. The adapter then fit onto the SLR's lens mount. Change adapters, and you could fit the same lens to a different brand SLR.
The adapter is not a teleconverter, nor is it an extension tube. It allows you to mount the lens to the body, and provides mechanical linkages between body and lens (iris control).