Nope, just tried that and no major change, still jerky and popping back and forth.
I thought it could be the font since its one i just downloaded but that doesn;t effect it, i even took off the grow/shrink effect and keyframed it and the motion is totally crappy. So then i narrowed it down to the effects. Turns out the bloom filter was causing it. Apparantly, even with an amount level set to zero, it still creates a nice brightening effect, basically bold-ing the font, so i dragged it out to the end.
Anyway, now i have it come to zero but then i have to end the effect on the next frame to make it go away completely and not affect the motion render.
If Motion had a way to put a faux bold on text, i could have avoided this. Or if Bloom just didn't affect Motion renders, that would work too
Note, I found that having the brightness up, even if bloom amount is set to zero, still affects it the brightness, nuetral brightness is actually set at 50, so i have to keyframe that to make a smooth transition