For sure the conditions DD, LD, PD, FS are all related as forms of Fibromatosis, and it is not at all uncommon to have symptoms and develop further stages of more than one if you are susceptible. It's less clear about plantar fasciiitus, that's probably just an inflammatory injury caused by overuse, misuse, etc.

More info here https://www.dupuytren-online.info/related_diseases.html and here https://www.dupuytren-online.info/frozen_shoulder.html

I had nasty plantar fasciitus that lasted a couple of years, from tennis and jogging. Tried nearly everything, insoles, orthotics, stretches, ice bottle rolls, spike ball rolls, massage, night boot, etc. In the course of this I discovered that in Germany at least they treat chronic PF with RT. Here in the UK I had the option of ESWT, which I did not have, but it cleared up during a rest period forced by an unrelated surgery. I was concerned that it would develop into LD but thankfully it did not. Sorbothane or similar quality insoles are in ALL my shoes.