Plantar is caused by weak feet. You have two choices: support the weak feet with inserts or strengthen your feet. I chose the latter. 60% of all people above the age of 65 that fall and break a femur or hip are dead within a year. Those falls are caused by weak feet.
Go get some zero drop shoes or barefoot shoes. Start exercising your feet and calves. It took almost 6 months of work, but mine finally went away and has never come back.
