Hi xwyokid,
I have seen Bigfoot coils having two mounting holes, one of them slotted, and requiring a special two bolt lower rod. The second bolt is an adjuster to set a fixed coil angle. I can see that it would be very difficult to use a Bigfoot coil that would not pivot. Is that the design of the Bigfoot coin you posted about?
I thought the two bolt design Bigfoot was only used for the 6.59khz models. I didn't realize any of the Bigfoot coils designed for the DFX/MXT/M6 were built using the two mounting bolt design. My Bigfoot and those currently for sale for the MXT have a one bolt mount design. This allows the the coil to pivot on the rod freely with only slight resistance. And, it allows the detector to be set down in the normal upright position. In fact, I often purposely pivot the coil to be parallel to the lower shaft using the toe of my shoe and pinpoint targets using only the tip of the coil. That pinpoint method is fast and very accurate on shallow targets.
You should see if you can borrow a one bolt Bigfoot or get a demo at a dealer. I think you will be pleasantly surprised.
Good luck and have fun, Bob