I think that depends on the type of speakers. Most nearfields are designed to be placed pretty close (3-6 ft) and directed at the listener, at ear level. In that scenario, moving your head will result in changes to the high end, of course. But our brains are very good at deciphering what is a change in the source, and what is a result of movement.
As the the tone boosters plug, it does do room emulation, though the algorithms are surely different from the VRM box. It works well enough, and it's free to try out.
If you do try it, though, make sure to calibrate it (finding good instructions for this is a bit hard, I found.) I did it by playing a mono track, then adjusting the head size, ear size, HRTF settings until it sounded like a mono source, directly in front of me.
Nothing is more important that being familiar with your monitoring environment, though. Hours in front of your speakers is the biggest thing.