“Family” prayer meeting

To the Rabbi Shalom
In our street minyan during the Corona period, a custom developed of sitting by family (each near the entrance of its own house), men and women together. The benefit in terms of Corona is clear, since the family lives together anyway and distance is maintained between the families. However, the arrangement is liked by the participants and a discussion has begun regarding the possibility of continuing it after the Corona days.
An initial examination I conducted led to the following conclusions:

1. The Talmudic sources on which the separation was based (Tractate Sukkah and Tractate Kiddushin) do not speak at all about a synagogue or about a law requiring separation in prayer, nor about fixed regulations.
2. There is no evidence of partitions in any of the synagogues found in Israel during the Mishnah and Talmud periods, but there is evidence of women coming to pray.
3. I did not find a discussion of the subject in the laws of prayer or synagogue in Rishonim, although it is known that there was a separate women’s section in synagogues in the Middle Ages.
4. The halachic sources on the subject are mainly the discussions of the later scholars who study the obligation of separation from the issues mentioned in the Talmud above and naturally assume that gender separation in the synagogue must be separated (the reason this is not mentioned in the early scholars is because it is obvious), and add to this various considerations of modesty (the prohibition of looking, speaking in a woman’s ear, etc.).

The conclusion from the above is that there is really no source in the first-order ruling for the prohibition of mixed prayer. The claim that the issue was not discussed because it was obvious, perhaps indicates the prevailing custom but not the establishment of a halakhic prohibition.
I asked:

1. Do you think there is a halakhic prohibition on mixed prayer between men and women, and if so, what is its origin? (I am not addressing the question of women’s roles in prayer, which is discussed extensively both on the site and elsewhere.)
2. Is there a difference in this matter between sitting according to families or just mixed sitting?
3. Is there a difference in this matter between a temporary minyan and a permanent minyan in a synagogue?

Thank you and happy holidays