The only problem with 'synergy stacking' is the perception of the players who think it defines the whole the game. The solution to that is to correct your perceptions instead of trying to fix what ain't broke.

The reality is that this game has a wide variety of content and is balanced holistically with that in mind. The optimal strategy for progression isn't necessarily the same as the one for speed, even light party and open world content have their own favoured jobs. In this context you can see that the game is actually pretty balanced with a niche for almost every job, I think it's folly to take something only 0.001% of the playerbase does seriously and try to shoehorn the entire game around that.

I think that the sooner people make their peace with that, the happier they will be because it's clear to me the game isn't going in that direction anyway. If you recall Yoshi-P's comments on why RDM's damage is fine, or why SMN's physick isn't on the level of vercure, you can see that things like job identity, and the big picture are a lot more important to them than narrow balance for balance's sake.

Personally as someone who grew up with fighting games and RTSes, I don't understand why some speed-oriented players are so insistent on having SE balance the game for them. If you operate on the cutting edge, your job is basically to find ways to break the game to your advantage, and you should expect to have to find and have to use all kinds of outlier strategies. When it comes down to it, this isn't really a performance oriented game either, even the hardest content it offers is structured around execution instead of raw numbers. Speedrunning is basically a community organized alternative activity that occurs outside the bounds of normal play, there is no obligation for them to balance around it. I mean, imagine if the whole community suddenly decided that open-world footraces was the new big thing, and people started clamouring for everyone to get the same level of mobility as dragoons and ninjas. Don't you think that would be a bit silly?