Hang on, I didn't read through your comment carefully enough.

It's word of god that Crowley has "pure, unfiltered non-binary/gender-fluid energy in general"... but the character is not genderqueer

For the purposes of a fic exchange, I feel that splitting hairs between "non-binary", "genderfluid", and "genderqueer" is counterproductive.

The character is canonically agender. The character canonically uses feminine presentation on more than one occasion, when said character has freedom to choose. Isn't that feminine enough?