One other thing - the fit on such things can be moderated by the actual barrel-size they are fitted-over. Which was a surprise to me, looking at how they are made
I have a pair of IEMs I like, bought spinfits in 2/3 sizes/ types to try over a period of a year or so - not the cheapest of exercises - and none felt 'quite right'. Seemed to seal, but a bit meh' on both sound and comfort, a split vote. I tried but could not achieve a satisfactory result by mix&match either - things merely sat at different depths, but neither 'right' nor ever convincing.
A few months ago I bought another pair of IEMs, but the barrel is maybe 0.4mm larger. Surprise: with the Spinfit blue, not only is the seal, perfect for me, but also very comfortable& easy to make&unmake, /and/ very comfort in use, splendid. I can wear for 3hrs + ...an absolute first for me and IEMs. This at the point I thought I really disliked Spinfit.
IEM fit, comfort & preference is both subtle, and very personal - but ultimately makes a huge difference in whether you can enjoy using what you have, at all. If 'recommended product X' doesn't work for you: just move on, for your own sanity.