As I recall, some skate boot makers want you to send your orthotics to them when ordering custom boots, so they can make sure the orthotics fit in the boots.
(That makes some sense TO ME. Your foot+the orthotic have to fit. And you don't want it to rock around because the bottom shapes don't match.)
But the way I see it, a properly fit custom boot should BE an orthotic, that fits you perfectly, and does everything your foot and body needs it to do.
Last I knew, one boot maker, Avanta (which includes some of Klingbeil's former staff), has a podiatrist at the factory store, who performs the fit, a process that included making actual full casts of your feet. If you don't live in the area, that might be an expensive route, but you are probably more likely to get a good fit. I believe they also accept fit measurements from some other podiatrists. Some people on this board have used Avanta, BTW - you could search it for "Avanta".
Why not call the boot maker you choose to find out what they think will work best?
BTW, I had a problem with stiff store-bought "customizable" (heat moldable) orthotics. (Or would you call them customizable insoles? I think of "orthotic" as something fit to you by someone with medical credentials.) They were a bit wide for the skates. They gradually widened the boots, until the boots were too loose.
I've been playing with the idea that if you make your own orthotics out of closed-cell foam (as I do, using closed-cell carpet foam), you can make them collapse asymmetrically to compensate for any asymmetry in the way your feet collapse. (E.g., if your feet set down on the ice in one orientation, but pronate or supinate when you put your weight on them.) In particular, you might be able to use a wire brush to turn the closed-cell foam into a somewhat open-cell foam on one side, or wherever you need it to collapse more, by popping some or all of the bubbles there. I don't have that particular foot problem - I collapse symmetrically.
But, since you like to play with equipment, if your feet collapse asymmetrically under load, you could do try it and tell us if it works.
The idea is to use an external orthotic to compensate for asymmetric support internal to the feet. But I'm not sure if you can pop enough bubbles with a wire brush to do enough, or gives you enough degrees of freedom to take care of all possible internal asymmetries - in part because internal support problems might be very nonlinear. E.g., a ligament or muscle might be loose, then suddenly come under tension when the foot collapses to a certain point. It MIGHT work to use the wire brush where needed only to a certain depth - so that part collapses easily, but the foam becomes stiffer once the popped foam is compressed. You might also need to experiment to get it right. Fortunately, carpet padding foam is cheap. E.g., a few dollars for a yard of 12' wide padding. Use the highest grade foam the carpet store sells, the one that requires more pounds per square inch to collapse (they are rated by PSI); otherwise it is too soft.
If you've the right feet for this, could I persuade you to try playing with it?