Remove required birtdate field for in3 (or make it optional)

[joeptwize]

For our client we have spoken to IN3 directly, because we wanted to remove the birthday field.
We dont want to ask customers their birthday, and IN3 replied that we could send 0 in the api, and it would still work.

But the mollie payments plugin has a required field for birthdate for IN3 payments.

Is it possble to filter this obligation in the code, so we could filter the value to 0, or filter it to make it non-required?
Or even easier, to make a setting for it, but im not sure if IN3 has removed the obligation just for us, or if 0 applies to all customers, thats something you guys would probably know.

Thanks in advance.