Sizing is difficult

So my partner and i have a few different caged ranging from a large metal one to a pussy, flat and even inverted cage, at different points throughout our week or even our weeken when we are having a bit of fun they all fit quite snug, but when completely sober or in the middle of our week these cages dont fit.

My erect penis is a humble 6 and a bit inches, but when completely soft, it is tiny and easily manipulated into the flat and inverted cages if we want.

What do yall recommend starting and progressing down with because my partner and i would love to shrink the cage as small as possible for on/off use

Would appreciate a few different options especially when downsizing thankyou