Today, events caused me to want to either delete, or severely alter that first reply. The problem? There is no option to edit!
Having no other clear path, I replied to my reply and — hopefully — people will see the reply.
And that, most recent, reply still has the “…” which, when pressed, reveals both the edit and the delete option.
Clicking on my avatar anywhere on that entire topic brings up the same user - the one and only one I’ve ever had - and the one under which I’m currently logged in, so I doubt the problem is related to multiple forum logins.
After talking with @Geo and @sjdorst at 3D Basecamp, we’ve changed the setting to…forever. You can now edit posts that you’ve made in the past, indefinitely.
Apparently, the Close feature does NOT affect the ability to edit existing posts in any closed thread, whilst Archive freezes everything. Came upon this over at Discourse Meta: