I have had one experience with orthotics built by a podiatrist, with all of the certifications, who also happened to have been a very devoted beer league ski racer. I was referred to the guy as he was really eager to show his trade to the program that my sone was in.
My son was no stranger to having a lot of boot fitting and plenty of footbeds made. He was about 16 at the time in a Matte Black Doberman. This was 15 years ago. The process took a lot of time. The footbeds just never worked. They were too rigid, took up FAR too much volume in the boot, and all in all just did not work. Basically on the shelf or in the closet after a day of training. Actually after about three runs. Back to the old footbed.
He and I, in particular have tried almost every footbed out there over the years, and we've gone more basic as time has gone on. He uses a very basic BD off the shelf footbed, and a basic off the shelf Superfeet in his AT setup. He's a coach, and has a coaching boot. He still free skis in a plug, and he has some alpine biased AT boots.
I use a ALINE off the shelf footbed, and incidentally a similar one in sneakers, hiking boots, etc. I use them in two pairs of ski boots.
Over the years, we literally have had pretty much everything. Custom foam, cork, semi rigid, etc. ALL built buy good boot fitters.
I have a HUGE bias to have boot fitters build footbeds for ski boots. That simple. Built for your foot, and your physiology to work in your boots. May seem overly simple.