I suffered badly with it for a long time and then I came across this and never looked back. In fact, I have not had an issue with it since I stated using it 6-7 years ago and don't need any kind of inserts. ProStretch Relief
To your background: I have plantar fasciitis also, and due to genetics I have flat as fuck feet. Basically flippers. I'm not significantly overweight (5'9, 200lbs) but I used to run when I was younger and I really never had a problem with foot pain until my late 20s after years of working on concrete surfaces with tons of walking in work boots (industrial maintenance, 10-15k steps daily just on concrete in work boots) and honestly nothing so far has helped me except for daily stretching, quality insoles (superfeet, treadlabs, etc) and eventually orthotic insoles from a podiatrist, and on the advice of the podiatrist, basically never going barefoot. I wear Oofos slides even around the house now. As for stretching, I bought this thing and use it twice daily barefoot, 30 second holds 2 per foot alternating and I do that while I brush my teeth in the morning and at night. When I don't do it I can tell after a few days. https://www.amazon.com/ProStretch-Blue-Stretcher-Fasciitis-Tendonitis/dp/B000GAAXGK That's just my story, the stretching absolutely can't hurt you and will probably help, for the rest I'd see a podiatrist if you can, because what causes my PF probably isn't what causes yours. Hope this helps or at least points you in the right direction, I know it's not literature like you requested but it's best I can do.
