DN: Would it be possible to design a DN proposal to specifically target women (i.e. only open to women applicants), if the lack of a gender bias within the field was well documented?

Designing a DN that is only open to applications by female fellows is not allowed in DN. The fact that the field has gender bias or not does not change these rules. Discrimination (negative or positive) is not supported by the rules.

COFUND: Would it be possible to design a COFUND proposal to specifically target women (i.e. only open to women applicants), if the lack of a gender bias within the field was well documented and clearly evidenced?

Yes, it is possible as far as it is well justified in the proposal. And this will then be up to the evaluators judgment.