Welcome Kelly. A good way to transition to minimalist footwear is to do it for everyday wear for a while. You can continue to train for Boston while building some foot strength in your everyday life. Once Boston is done, you can start experimenting with your running.

Thanks for the advice Damien. Shortly after your reply I bought a pair of VFF TrekSports and I've been wearing them for a few hours each day at work. Anecdotally, when I bought them I was starting to have moderate pain in my Achilles from all the running, but that has gone away since I started wearing the shoes. After almost a month of wearing them casually I can tell the muscles in my feet are stronger. So far so good!

No problem, glad I was able to help in some way. Sounds like you are heading in a positive direction. Taking things slow, seeing a reduction in pain, and feeling like your body is getting stronger are all excellent signs that you are doing the right thing. Keep up the good work!