I think the heart of the difference between our views from what I’ve been able to understand from you is this. You view biological differences between men and women as having a sufficient enough reason to support gender roles if in the event the capability of a couple is known.

I view the biological differences as something that should only be considered from a health perspective I.e. crash test dummy’s designed for men and ones designed for women to ensure proper safety testing.

For me the biological differences shouldn’t be considered whether we know a couple’s capabilities or not. Humans are an extremely varied species with lots of overlap between women and men.

There are women who are tall and muscular and men who are short and skinny. There are men who are tall and skinny and women who are short and muscular.

Ultimately the biggest factor is lifestyle and not genetics. A female firefighter could absolutely out strength many males even if she’s short because she works out regularly.

In short I don’t think biological differences are significant enough to be taken into actual consideration outside of specific circumstances like described above. While you as I understand it do believe them to be significant enough a factor to be given consideration if the differences between a couple are known.