After 40 years of running 20+ miles a week. I had bone spurs and arthritis in my feet. My big toes were down to 20% of the normal range of motion. I had surgery, similar to bunen surgery, on both big toes to remove the spurs, straighten the toes, and give me more normal range of motion. Of course I was also told my running days were over. So I had to find alternative outdoor excersise options after my recovery, with less impact on my feet.
The surgery was a success, but I have some nerve damage from the surgery on one foot that does not allow me to apply high pressure in that area. The regular cleat position really iritated those nerve bundles, limiting my rides to 10-20 miles. Moving the cleat to midsole totally fixed all my issues with riding. I can now do 100 miles with no foot or toe pain.
Note my bone spurs also iritate my achilles tendon attachment, and when using a midsole position you use your calf muscles and achilles less. So less iritation there for me also. Win win!
Sorry for long story, but you did ask.
Mark