[MC5C]

My experiments with archtop bridges, of which I've made a bunch, are that surface area of the "feet" has a dampening effect on vibration transfer but a beneficial effect on top wear, that lighter is always better than heavier, that stiffness is beneficial, and that sometimes practicality over-rides minute sonic advantages. Ken Parker has made bridges of hollowed out spruce with a bone saddle - in my world that is pretty **** good, it has a small footprint on the top (the perimeter of the hollowed out base, it's very light, it's very stiff, and he has an adjustable neck so he doesn't need an adjustable bridge.

As far as surface area of the feet to transfer vibration to the top, imagine a really simply experiment. Tap an old time tuning fork and touch the ball to the top of the guitar. Instantly a loud, clear tone emerges. The surface area of the interface between a sphere (the ball of the tuning fork handle) and a plane (the top, or the edge of the bridge foot) is theoretically zero - where they touch defines a point, of zero dimension. If that point transfers energy so well, why does a big, flattish, massy bridge foot, one or two of them, improve on that? Answer - it doesn't, it dampens the energy of the transfer.

After making all the bridges, and testing all the ideas, I went back to using a typical bridge with two threaded rods and and spinny adjusters, so I could focus on playing and not on what humidity changes were doing to the set up of my guitars. Practicality trumped fleeting perfection. On my guitars, to get them to play the way I need them to, I adjust both bridges and truss rods monthly, if not weekly. I play with very low action because of nerve damage in my left hand.