I get asked this a lot, so to set the record straight, a high arch or flat feet is not a problem foot or “wrong” so it doesn’t need to be “fixed”.
I have seen a high arch become lower by the client wearing an orthotic with significant realignment structures built into the orthotic but the client ended up with plantar fasciitis pain for years afterwards. I’ve also seen very flat feet with bunions and hammertoes return to almost completely normal-looking feet in one year but that client was a high-level athlete that religiously did the exercises that we gave her to strengthen her feet as well as wearing the orthotics all the time.
So it is possible to cause some realignment of the foot or parts of the foot with an aggressive orthotic but more often than not an aggressive orthotic causes a significant amount of pain, enough so that the client stops wearing them and ends up without the outcome we were hoping for.
My strong tendency is to accommodate rather than correct, it’s more comfortable and tends to bring about a more positive result.