Note: this likely applies across all systems, but I’ve tagged it as iOS since that’s my system of choice…
See attached screenshot - when a weapon is sealed, I don’t receive it in the normal level up options (expected) but then it shows up in the limit break menu, clogging the item growth (and since I’ve explicitly sealed it, it’s pretty much useless to me). Screenshot is from a sealed Flames of Misspell, which is still at level 1 (as can be seen from the screenshot).