tadawdy

Your question is one that competitive cyclists have asked. To answer in short: placing the cleat further back is not necessarily less efficient. Most studies on the matter compare the typical placement (beneath the ball) with a mid-arch placement. No differences are typically found, and the authors often wonder if it isn't actually more efficient; if they're just as good using a position they never practice, what would happen if they practiced that way? This is just speculative, but a worthwhile question.

For someone in your position, it would be typical to move the cleat backward. Moving it forward would increase the demand on the triceps surae (calf muscles) and Achilles tendon. It isn't something most people would advise.

If you move your foot forward (cleat backward), you will probably want to change your saddle position to compensate. If you move it really far back, you'll have to watch out for toe overlap with the front wheel, but this is usually only a problem at very low speeds.

The rearward cleat position is not good for standing to sprint or climb, though. It is usually used by triathletes and long-distance types, who require generally constant effort. Plenty of RAAM types have put their cleats very far back for various reasons, and recommend doing so. Not that that proves it's the best for performance. it just shows that some people find it to be a good solution.

Try adjusting your saddle, and give yourself some time to get used to it. It isn't rare. It isn't weird. Just try it.

I actually was thinking about this today, because I have a bunion on one foot that will probably give me grief someday. It's comforting to know I can probably just move the cleat back and keep going. hopefully, it'll hold off until I don't care one iota about going fast, and am just happy to be able to ride. I've tried pushing my cleat back, and settled slightly behind the ball. If i had to drill my shoes and put the cleat on my heel to keep riding? Sure.