Snickers:
In response to your question, "how often," I can only tell you what I did. I updated (meaning re-applied) every time I heard the window was open. That was roughly every 3 to 6 months.

I only had one internal who was a brand new captain (FO at the time).

I'll swim in the pool as long as I have to, but I'm hoping it won't be much longer! Good luck to those of you awaiting calls and who are already scheduled to interview.