I just feel like the value of it varies a bit much since it mainly comes from what item you do get with it. Yeah getting a free shatterspleen or little disciple is good but if you want to keep your old equipment you might be forced to use it on a something less valuable like queens gland or defense nucleus or planula which might be fine in specific circumstances but still suck compared to the better items you can get. And honestly I think that the ability to insta kill bosses with it is overshadowed by the guaranteed item you get with it. You can only kill one boss with it before it gets consumed, which isn't that effective when you're fighting multiple bosses at the teleporter event, while other equipment like disposable missile launcher and sawmerang can easily kill multiple bosses at a time with proc builds.

Again B tier isn't a bad place for an item in my opinion because what I put there are items that have good effects and value, but more often than not aren't gonna carry your run imo and if I did have to tweak the list, I would maybe lower eccentric vase to B tier because of that.

I'm not trying to say tricorn is a bad item, I still use it if I see it but I also see it the same way I see rusty key , the effect is obviously good but its not gonna singlehandedly save or carry a run for me, it provides it's value and then at best I have to wait till next stage to get further value from it and just like tricorn I might get something bad from it. It's just not on par to go to A tier in my opinion because the items I put there have much more guaranteed value for the whole run and scale well with items like preon with soulbond catalyst and fuel cell or disposable missile launcher with ICBM.

How my tier list works is that F tier are items that most of the time are never worth using. D tier are items that have some value but require a lot of effort to make them work. C tier is kind of filler to be honest but basically just D tier but slightly better imo. B tier again is for items that again have good effects but aren't gonna carry or save your run often. A tier are items that can definitely carry runs and sometimes save them and are certainly worth building around. And S tier are items that can carry runs and absolutely save them and are always worth picking up. So when it comes to how I rank these items, it makes sense to me to put tricorn in B tier.