Fleshlight anti-slip-out thing
The fleshlight ring will become easily slip out when they age or if you use it rough. 4 of this little thing can hold that down for good.
With the elephant foot defect, some of my prints snuggly fit it, but after I fix the elephant foot issue, it will be a bit too small for the first channel on the fleshlight case. Putting some tapes on it will fix it.
It only takes minutes to print one, maybe you should print one and see if that is too large or too small for your fleshlight cases, and then print more. I found 4 of them can hold the ring down real good.