I don't believe it needs to be perfect. But should be in the same sky area. Tracking errors are different between the celestial pole and the celestial equator.
The question is - would you benefit of anything better than 0.7-0.8? Are you planning on shooting long FLs and cameras with tiny pixels, and in location where the seeing would make sense to go more precise. If so, give it a try and let us know how you go
