I would I suggest you fix it? I haven’t got an answer. WP_Query cannot be used to sort these values in any meaningful way. I suspect that this is one of the reasons the save format setting was removed from later versions of ACF.
You can still use the return format in ACF, as long as you are using get_field() to get these values in your functions then those functions should not be affected by what is stored in the database.
I’ve started to type suggestions several times and deleted them. I can’t even come up with a valid plan for replacing all the fields in the DB. In the end I would likely create a new field, manually update every product and then re-code the site to use the new field. This would be a big job.
