I have Lamellar, but if not for the difference in foot size, my feet and yours look very similar! I don't get blisters but I do get a lot of cracks during winter & summer, especially if the weather is severe.

I'm assuming you do something to both moisturize and exfoliate your feet. I've found that preventing my feet from drying out so that I don't have to exfoliate is the best course to preventing problems. I've also found that natural ingredient based moisturizers tend to be far more effective than most of the stuff that's got acid components (Amlactin, etc.) or petroleum bases. Have you investigated using cocoa or shea butter? I'm pretty wild for Palmer's Cocoa Butter and Vitamin E balm but it's expensive. My skin soaks it up instead of having it just sit on top thus it's a much more effective moisturizer though it means I do have to apply 1-3 coats before I can put on socks or shoes.

I don't know how to prevent the blisters since I don't get them but I'm curious if friction is part of the problem. Does friction irritate your palms and soles? It does for me. You might laugh at my next suggestion but I figure it can't hurt to share. I have found that wearing hand knit socks makes a HUGE difference. Because I knit them to fit my feet, there's less friction and for the past three years, I've managed to avoid having any cracks and splitting. I suspect some might think "hand knit socks will help" is a ridiculous answer, but the difference between something that's created to fit you versus one size fits most is dramatic. Thus in all seriousness, I recommend you learn to knit or you bribe someone to knit for you. I'm still busy trying to knit enough socks for myself so that I don't have wear store-bought ever again.

Also, you will want to wear shoes with the absolute best support for your foot that you can find/afford. I have high arches, thus I make sure I wear shoes with lots of arch support otherwise that can cause my soles to split, too.

I hope some of this at least gives you ideas.
I am female, and was born in 1972 with Lamellar Ichthyosis.