For substances unsuitable to handle by the average person when undiluted,

So basically everything? Most cleaning chemicals are already dangerous, now they are going to be more concentrated. Theres dangers in mixing, so now the store should have an employee to mix it, this can solve the return issue as well, but comes with its own issues.

Training, ppe, space to store hundreds of Chemical totes. Building codes and local bylaws probably have something to say about concentrated chemicals being that close to residential areas.

What if the crack and mix in the store? In those concentrations and amounts, that’s mustard gas that’ll take out the town.