An Ashkenazi and Sefaradi (Edot Hamizrach) are getting married. They each have available mezuzot from previous houses they lived in, written in Ashkenazi (Beit Yosef) or Sefaradi (Vellish) script.
Are there halachic sources commenting on whether they can hang these mezuzot in their new dwelling independently of the script of the mezuza? Do they have to follow the husband's custom or can they also reuse the wife's mezuzot?
Does it matter if they are moving into a new apartment (without mezuzot) vs. the apartment of one of them which already has mezuzot? In the latter case, does it matter if it is the husband's or wife's apartment?
PS. This question is related but appears to be asking bdieved and without the (potential) attenuating fact of different customs for husband and wife.