This is an interesting idea... though I probably would not end up using it. Here are my concerns/thoughts:

1. Freeze dried meals are already pretty expensive, adding individual customization would certainly make them more expensive. I guess if you were not the one customizing it but say you sold individual packets of components that gave the person the opportunity to mix and match what they like then you could perhaps be cost competitive with what is already on the shelf at REI... it would also give you the opportunity to be on the shelf at REI. I'm thinking of something like column 1 being starch options, column 2 being sauces and column 3 being proteins. Grab one from each and you are good to go. Want more protein? Grab two from column 3.

2. Time... How long would it take for you to customize a meal and deliver it to me. If I have that much lead time I do it myself. I buy freeze dried items when I have not prepared for a trip. I just grab something at REI.

3. The other problem with customization is people will make terrible decisions and blame you. You have to find a way for your product to be good even with your customers terrible ideas. One example of this is Mountain House publicly said years ago they were developing lower sodium options. Nothing ever came of it. I am guessing they came to the conclusion they lower sodium meals tasted so bad that people would only buy them once and then have bad connotations with Mountain House. People should have lower sodium freeze dried meal options but there is not a market for it as far as I can tell.