Off topic: I like these transparent mod comments you have been doing! Do you set a flag to keep them at the bottom or do they get so few upvotes?

Glad to hear it!

That's exactly right. There's a flag for off-topic subthreads that I put on most of these, so they don't interfere with the real discussion.

Is there a flag for disabling edits of certain comments?

There was a bug I fixed the other day that was shortening the edit window on comments. That fix was temporarily lost when the server restarted, so my guess is that you were affected by the rejuvenated bug—in which case, sorry.

The fix won't be permanent until I find a few hours to get back to the damn code. But at least it's live at the moment.

Editing is disabled a certain time after the comment is posted, perhaps that is what you have observed?

It was well under 2 minutes.