Like it with one corollary: If the intent is to buff an off-stat, treat it like rage, with the dex mod being the time determinant, just as con is for a barb. That'd mean a STR build would get the effect for less time, but doesn't loose as much burst to burst. (Presumes they keep the dex devaluation as present when it comes to physical damage. If it actually will become a meaningful difference between defense and offense, by all means, stack em for the same length of time.)