Have you considered a food co-operative? The 3 co-ops.I gave been active in plus a few others where I've shopped (all in different cities and villages), were sensitive to food allergies.

I was livid with Whole Foods Market was bought out by Evil Amazon. What can we do? All Allergy only stores close up. Grocery stores only carry "what corporate allows" and no grocery store actually cares if we live or die. I came up with some plans that are iffy, but they are ideas. Some are better than others for obvious reasons we don't need to discuss.

Plan A - Thus, the only option we have left is a class action lawsuit, suing for mega-billions of dollars and naming every single major grocery store in the entire country in order to get the government and the priviledge Rich fools to understand that we need to eat something! And can't just "make do". With any luck, this will get so much extreme media coverage that companies would be forced to change their policies.

I use to sign petitions, make phone calls, and so on, but gave up after I realized the stinking greedy rich owners don't care.

Plan B - I don't have the brain for it, but maybe you do. Find people who can start grocery store business with factory sized green houses (multi story) so that we can have foods not cross contaminated with other foods. We'd manufacture as much food as we can from those green houses. Basically, we'd be the grower, maker, supplier and seller - cutting out the evil rich people who want us to just "make do". I also think Plan B has a better chance of working, but only if someone who is very good at transportation and getting this cost down. (Outsourcing does not work very well and leads to drivers not getting paid. Research delivery services that went out of business after hooking up with Amazon).

Plan C - Might work, but doubt it. All people with food allergies who shop at Whole Foods Market, write emails and call and complain to the CEO of Whole Foods Market how we can't get safe foods anymore and that no grocery store carries what we can safely eat and we need to eat! If thousands of us complain, then maybe we might get relief. Problem - in your specific area, you might not have hundreds who buy your products you need. My nephew and I needed vinegar free ketchup. Whole Foods before Amazon refused to carry it because it just didn't sell. I find this is the issue with all grocery stores - Kyt Friendly does not sell. Majority wins.

Plan D - Maybe, with any luck, we can get the government to come up with a solution forcing grocery stores to carry the specific product by the specific manufacturer we need by request if we submit a doctors note of allergies. Outside of the USA, I'm told England is more Allergy aware - and more corn free.
Best Wishes!