Technically that's what TP and weaponskills were meant to be for originally anyway - in FFXI and FFXIV 1.0 you started with zero TP and gradually built it up by simply hitting the enemy with your weapon (or the enemy hitting you), until you accumulated enough TP to let rip with a weaponskill. Needless to say this form of combat was very slow and thus SE decided to speed it up considerably by giving you maxed TP at the start by default that is gradually drained by spamming weaponskills over and over again.

Really I don't think we need a separate solo Limit Break system - we already have the party one so that encourages players to work together. Not to mention regular weaponskills already combo off each other for added effects. This is just merely rehashing what is already in the game for little benefit.