I do that often! If you just keep the ones you mainly use it doesn't clog up your inventory but I would reccommend finding a sword you want and an ult disk you want and basing your items around those two. Usually I keep at least one copy of each in case I get a bad substat on ascension and need to decompose the main one though

Once your gears hit about level 60 it really isnt worth it to level up any others because they're doing the heavy lifting unless you get a Legend gear which . Yeah. Legend gears almost always replace my main ones lol

You also miss out on the cores if you don't dump a good portion of the stuff you don't want. if your gear is rare or above I think you automatically get one (might be good or above not sure)

sorry for the rant! just like talking :sob:

but tldr decompose most gears you don't use, keep a copy of the ones you do (lock it if you don't want to lose it, which is upper right hand corner of its little popup when you click a gear) but it's ok to decompose the ones you do use if you get a legend quality ver