In the mean time, perhaps France would consider adopting the approach used in many German cities whereby monthly pass holders are permitted to take another adult and 3 children for free during evenings, weekends, and holidays. [1] Many German cities also offer cheaper subscriptions if you only use public transit after 09:00.
This is great if you have a visiting friend, or a partner/family who do not have monthly passes but want to go somewhere outside of business hours.
The RATP still considers weekly passes valid from Monday to Sunday and monthly passes valid from the 1st to the end of the month. They do not sell passes pro rata (e.g. if you buy a monthly pass on the 10th, you pay the same as someone who bought on the 1st), nor do they offer 7d/10d passes. They recently introduced Navigo Easy to replace tickets, but this is limited to trips in zones 1-2. [2]
The fact that RATP are still this inflexible in 2021 does not give me confidence they can become more progressive.