Hmm...I'm all for having to get the EX weapons to upgrade the Zeniths more, along with needing the new Tomes. Heck, even having to make and meld an i70 wouldn't be bad to me either (the fact that I can craft some of them and bug some friends for the rest doesn't have anything to do with this...)

I'm sure there will be a quest-chain to do this, though. Probably have to beat Township (and maybe Halitali HM and Brayflox HM) to get some item(s) and use that in the upgrading or something.