I dropped my full 24oz hydroflask and damaged the base enough that it would not sit flat on any surface. It was like a weeble-wobble. After adding the boot, the bottle is stable again.
I printed this out of Eryone 95A TPU on a MK4S using the generic FLEX profile. I made slight changes to the temperatures based on what was suggested for this filament.
It fits snug over the bottle. Enough so that its a bit difficult to remove. Problem solved.
The author marked this model as their own original creation.