Phil,
I think life would be easier if the basket could easily detach from the shaft so you don't need to remove the entire frame to empty and reload. I see the solution sitting on the side of the tank from that process and it's messy. If you were to cut the main shaft leading to the basket just under the tee the shaft spins in and glue on a coupling to one piece of the shaft and slide in the other end and pin it with a small nut and bolt, it should be easier to just remove the basket. You may have to sand the pipe a bit for the slip connection so it comes out easy.
You may have to reconfigure the dangler a bit so it isn't in the way but freeing up just the basket with a short length of shaft will make rinsing and reloading easier, you could even make extra baskets so they can dry out between rinsing and not dilute your acid too much.
Just a thought.
All in all you did a very nice job, thanks for sharing it with us.