say both spouses come to mediation, agree on the issues, and sign the mediation agreement once all negotiating is done.

my understanding is that someone or someones attorney then needs to actually file the mediation agreement in a court correct? for a judge to approve?

what happens hypothetically if neither side files or does anything after mediation, and just leaves the agreement hanging? signed but no next step so it never gets to an actual judge?

after X days does the mediation agreement expire? or can one spouse whose financial situation improves say 1 year later file the 1 year old mediated agreement and then essentially get a better deal because the signed agreement was based on old data?