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I don't know what equipment you are using (mount!) but polar alignment is always a compromise. There really isn't such a thing as "perfect alignment" unless you are speaking of a small area of the sky for a relatively small period of time. Refraction changes with altitude and with temperature and humidity so it is impossible (as best I understand!) to align perfectly and have no issues with tracking.
However, it is possible to use programs such as TheSkyX/T-Point to achieve different polar alignments that are very close for what you want to achieve. In addition it is possible to "model" the mount/scope combination so that flexure and things like non-perpendicularity of the scope to the DEC axis (and many others) are then compensated for during tracking. With high end mounts like a Paramount or AP (and others) it is possible to go quite long unguided if everything is exactly right (not easy!!). Most imagers probably guide just to compensate for any residual error.
Anyway, to answer your question as specifically as I can, I think that if you are inside of an arc-min in both altitude and azimuth, I doubt that you will be troubled by rotational effects. What you might want to do is drift align in the area of the sky you intend to image. You will find that a drift alignment at dec=0 will be different than drifting elsewhere. The benefit of drift alignment at DEC=0 is that motion in RA is maximized. As you move closer and closer to the pole the velocity of the tracking arc decreases (not the mount motor, but the actual speed the star appears to move across the sky). Anyway, sorry if I sound like I'm lecturing!!
Peter
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