Does Plugging Bass Port Affect Pace, Rhythm and Timing?

Monitor Audio dual ports some of their speakers specifically for boundary tuning. My Silver 300 7G were a bit thick on certain vocals. Plugging both was too much, plugging the top port, too little, and plugging the bottom port, perfect, with no loss of extension or dynamics. Ported speakers roll off at 24 dB/Octave, sealed ones at 12dB/Octave. Porting at best gives another half octave of bass before rolling off. As for being below the tweeter axis, it's not the tweeter, rather you are in a phase cancellation lobe that's a function of driver spacing, crossover frequency and slope. Regardless, the fixes which you discovered are correct: the goal is getting more on axis with the tweeter. Actual tweeter dispersion is a function of driver diameter and wave guide (if any).  Remember those wave tank experiments in HS physics? The narrower the aperture the wider the dispersion, but the lower the output on the other side. Exactly the same with speakers.