How long before switching to a smaller device

I’ve been wearing my device for almost five months now, and I’m seeing some shrinkage. The cage length is currently around 60mm; on certain days it stays tucked in tightly, while other times it retracts by about 20mm.

I trust that our bodies give us good signals regarding what works best, but hearing from others about their timelines before transitioning to a smaller device would be helpful too.

Also, which steel devices are the most suitable? I have a PA piercing. Currently wearing the Black Tiger Ridem by Chain Gang. gregstep427:?: