JB size considerations

The JB works well for me, but I could use some guidance on the cage dimensions. Usually, I’m comfortably pressed against the back end, yet in certain seated postures like driving, I retract slightly. When I move forward again, it rubs and catches near the top, requiring a gentle finger adjustment to realign. Lube helps temporarily but isn’t a permanent fix. Even when fully extended, my shaft doesn’t seem to curve as much as the cage does. So, is the cage perhaps too long?

Separately, the JB tends to rotate leftward regularly. I believe the gap spacing is even, so I wonder if it’s due to an oval-shaped base ring that offers more space on the left side than the right. It’s not a major issue, but I’m considering whether to make the base ring rounder.