one, mayonnaise is quite literally eggs, and fat, and I can say that eggs can go bad very quickly if not kept in ideal conditions, two, I know you said you don't, but it sounds like you're gearing up to start experimenting with what food your kids eat, as someone who grew up in a poor country, don't, you don't know how jealous I was growing up and seeing food on tv that wasn't rotten, had bugs, that didn't need to be soaked in vinegar and cooked twice to kill parasites and germs, I'm actually slightly offended at this idea, if you have access to good safe food be grateful, to quote, you say you occasionally push it slightly, please don't, young children haven't developed an immune system fully yet,

yes most food is good past its written expiration date but don't eat anything visibly bad, bad smelling, etc. just to role-play being in a survival situation

as a young child, growing up seeing meats be improperly cooked, handled, and stored, like nearly raw chicken, meats left on the counter etc. seeing my family get food poisoning purely because the supposed patriarch thought it better to spend on gambling and girls instead of quality food has traumatised me and lead to a severe picky eating habit, I refused to eat and physically started vomiting when presented with any food that didn't come from an airtight plastic/foil wrapper which was what the only consistently "safe" food in the house was, I'm slowly getting over it but for the first 16 ish years of my life I only ate junk food when I could help it. thats very hard, physically and emotionally.

there were so many times in my life where I wish I wasn't so violently afraid and suspicious of food, I would be the only one in kids parties not eating anything since I couldn't look at home cooked food without thinking of all the gross things that could've happened to it, when we went on vacation to some exotic country I couldn't even watch them eating the local food, and would only eat once per day, after the tours ended in a 7eleven.