Might it not be a good idea to NOT train in racing flats at all initially, but rather to wear them all the time for daily activities (or as much as possible) allowing the ligaments, tendons and connective to begin making adjustments?
Is this a practice anyone else has tried? If so, how did it work?
bump
Begin walking barefoot on grass as much as possible. 10-15-20 minutes day or mor eif you can. After running, start adding barefoot strides or jogging to your cooldowns. 5 minutes jogging one day, some strides, then run normally. If all is well, 8 minutes jogging, the some more jogging and strides the next day, then a third day with jogging/strides, then back to normal. Keep evaluating and increasing by 5 minutes a day until you are comfortable running barefoot 30 min at once.
If you live in a cold area, get a Nike Free or Puma H Street.
Change your street shoe to the H Street now and walk around in that. Do calf raises with the soleus and gastroc (bent knee/straight knee) lowering slowly. All of this should help you transition to start running in flats. 5 minutes, 10 minutes, very gradual until all your running is in flats.