Can orthotics assist the healing process of a stress fracture?

Yes. I did a little research a while back on this. I found that orthotics generally reduce the risk of injury and stress by 41% and 74% respectively. Orthotics spread pressure (reducing stress) and align the foot giving room and time for your foot to heal. However, the same research cautioned that wrongly prescribed orthotics e.g. DIY or Over-The-Counter orthotics can be detrimental rather than helpful. To source fitting, custom orthotics use platforms that have on-staff podiatrists to help you make the right decisions.