We have a thing that gives party a speed bonus, its called swiftsong and it is not usable in battle since its clear squeenix sees it as too much of an adavantage just as party-wide stoneskin.

5% or 10% would be too high, but I can see the advantage of 1% increase. Its not going to break the game, but it just might be enough to change insta lag kills to kills due to legit mistakes. 1% is still better than nothing imo.