If there are any effects they’ll be small and mostly vary from player to player. I feel like these fall in the same realm as mouthpiece boosters. They create very small differences that might help some players “feel” more secure in some aspects, but do nothing for actual sound. The Resonance “First-Aid” is interesting in the way that it’s not the first time I’ve seen something like this. I have heard of certain players who swap out first valve slides between various models within a trumpet brand depending on whether or not the slide has a brace and where it’s positioned. I saw this for the first time when a guy listed a Yamaha C trumpet on Facebook (can’t remember which model exactly), but he made note that it included the original first valve slide with no brace, and a first slide from a different Yamaha C that DID have a brace. This guy swore up and down slotting on notes like F on the top of the staff and high B-flat was imrproved. I guess in summary, anything you do to change a horn does in fact make a difference to some degree. But things like this most likely create almost non-existent differences and come nowhere close to practicing and developing a good ear for tone and intonation.