Hi @szaleq
Thanks for your feedback. I don’t really understand why you are creating custom fields which do not have a label or name, this doesn’t make any sense to me.
I’m not sure If I will add this to the to-do as so far, you are the first user to raise this issue.
Perhaps you could think about hooking into some of the ACF hooks such as acf/update_field to run your own validation?
Thanks
E