Maybe this is a little too precious, but I change out from a metal cage to a polycarbonate cage seasonally, so that when I’m using my vacuum-insulated, double-wall stainless steel Elite Deboyo Race bottle in the winter to carry hot tea— what a treat!— it doesn’t rattle.
I like the Supacaz Fly Cage Poly:
https://supacaz.com/product/fly-cage...neon-purple-2/
I like the look of my rainbow anodized Ti Fly cages better, though, so I put them— well, the one that got swapped— when I’m back to plastic bottles in the Spring. It’s a bit of work, but taken as part of winter maintenance and “spring cleaning,” it’s not burdensome. It does scuff my anodized aluminum cage bolts, though; I should go Ti there…