It does sound like you are near the end. Just keep in mind that the easy stuff that oxidizes readily has been taken care of, but there may still be some remnants of partially oxidized CYA that will be somewhat slower to oxidize and get rid of. You are definitely close and should see your total chlorine demand go way down at this point.

So if your CYA is low, raise it so that you don't lose too much from sunlight during the day. You should have it at least at 30 ppm, but 50 ppm is fine as well and is more typical for pools in the sun (pools in a LOT of sun, such as Arizona, sometimes operate at 80 ppm to minimize chlorine loss, but you have to be very diligent about maintaining chlorine in such pools since it takes more chlorine to shock them to get rid of algae).

It's interesting (and somewhat comforting to my nerdy personality) that the total amount of chlorine needed was in the ballpark of that predicted based on the CYA loss, which was a rough guestimate to begin with.

Richard