I should note that I am sort of on the fence myself regarding the sexual dichotomy philosophy promoted by Deida, but I will write here as though I am direct advocate.Ego said: I like the kind of interdependence where each person is helping the other to strengthen their weak areas rather than splitting the work by strengths. We are both very cognizant of the fact that one day a terrible thing could happen and one of us might not be here. Recognizing that possibility makes us appreciate this moment, right now, and encourages us to continue improving and growing as individuals as well as a couple.
I think it is excellent that you are self-aware about the very real possibility of race-to-the-bottom dependency in long term dyad relationship. One of the reasons I really regret not taking a strong stance sooner in my marriage is that I seriously ended up Harrison-Bergeron-ing myself for a number of years. A monogamous adult dyad can only hold together if there is not too great of a division in the powers of the individuals engaged. In fact, one theory is that in the moment you are choosing to have sex with somebody, you are necessarily at equal power level. This is what is often being conveyed with a statement like "I only had sex with that person because I was drunk." IOW, there is an essential conflict between maintaining the dyad and personal growth which will result in tension that can either be resolved in a dysfunctional manner (unconscious sink to lowest common denominator) or a functional manner (self-aware disinclination to sacrifice personal growth combined with ability to hold on through tension of temporary power disequilibrium.) Also,the dyad is "we", but sex can only occur between "you" and "I." IOW, the affectionate dyad can be maintained without individuation but the sexual dyad can not because humans are out-breeders, so sex is about difference, whereas "liking" is about similarity. This is brief summary of the basis of modern egalitarian relationship theory not necessarily inclusive of sexual dichotomy theory.
So, modern egalitarian relationship theory holds that individuation or "differentiation" is necessary to maintain sexual tension in long-term relationships. Sexual dichotomy theory states that this tension and attraction will be greatest if one partner presents in strong feminine energy and the other partner presents in strong masculine energy. IOW, if the power held by each partner is strong and equal, but different because one partner is holding open, receptive energy while the other partner is holding focused, directive energy.
The traditional division of labor along sexist lines is only remotely related to feminine vs. masculine energy. It's not what you do. It's how you do it. In fact, if you are "do"ing, you are almost certainly in your masculine energy. You are in your feminine energy when you are "be"ing. Many or most endeavors involve both masculine and feminine energy. For instance, if I am in my garden and I am measuring out rows and making notes on graph paper then I am in my masculine energy. If I am in my garden and I am hunkered down smelling flowers, feeling the sun on my back and tasting fresh strawberries, then I am in my feminine energy.
Anyways, something you might ponder would be if, for instance, you are helping Mrs. Ego to be able to hang from a gutter by herself (metaphorically as well as literally), are you imagining a future in which she will be alone because you are gone rather than a future in which she will be best able to attract a new partner with enough muscle to pull her on to the roof and vice-versa? I'm not implying that the two are mutually exclusive, but we all need to make choices about in what way we wish to improve or what direction we wish to grow. For instance, it would or could be a strong stance in alignment with individuation if a partner said to me "I am going to teach you how to weld this afternoon." (has happened-lol) and I replied "No. This afternoon I will be shopping for a pretty dress at the thrift store and getting a pedicure with my sister." and then just blew him a kiss when he starts muttering something about "useless females." I get that it's a terrible burden on one's freedom to be the only one in the room who is capable of doing a decent job of welding, but ...P.O.P. (price of pretty- get your mind out of the gutter.) This is a simple, superficial example of individuation towards or in alignment with sexual dichotomy. The highest manifestation of feminine energy would be something like being completely relaxed in trust in relationship to the universe.