Since we're already in the chef_wm_enforce module, I would be tempted to pull the validation function out into a separate function like `valid_max_size`. Not sure I'm following the intended contract for return from validation fun in envy. Can you return anything? Will the logging already wrap info about `{chef_wm, max_request_size}` as the key in question (I think so).

The most useful thing in the message would be the bad value itself.

If nothing else, I think `disabled_is_only_non_integer_value` will be rather confusing.