The old adage that you can agree to differ is always useful to remember. Nobody has to win in a disagreement. Rather, the focus can be on each partner listening to and understanding the other's point of view. Develop your own autonomy. In order to prevent resentments you might take your partner's dissertation writing time to increase your own autonomy.
Autonomy can be a self- esteem builder.
Balance autonomy with connection. Similarly, you can take time to acknowledge your partner's pleasing behavior. Sometimes well meaning partners can advance their own agendas to move the dissertation along by giving unhelpful, unwanted, and unsolicited assistance to the dissertation writer. Unhelpful helping can be reduced and prevented. Listen to your partner's requests for help before jumping in.