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You can sync near the pole (As it is unlikely you will be pointed exactly at the pole) but it is not a good idea as it is error prone. As Steve pointed out, if you are pointed directly at the pole RA is undefined. If you plate solve at the pole and the plate solve result is on the opposite side of the meridian from where EQMOD assumed the scope was it will reject the sync. That one tripped me up getting meridian flips automated at one point due to cone error, after the flip the telescope was pointed just a few minutes east of the meridian and it would fail there. Delaying the flip an extra ten minutes solved it.
Make sure your polar alignment is good, then the park position is reasonably accurate and do your first goto. Then polatesolve and sync. Or even just randomly point off to the east somewhere and plate solve/sync will do, just get away from the pole and meridian.
It was mentioned above about syncing multiple points which builds a pointing model. I Know APT recommends working that way and when I was using APT I had a routine down which captured maybe ten sync points each side of the meridian (Append on sync) before I would start imaging after which gotos were quite accurate, but it still usually took more than one pointing iteration to get right on target.
SGP and Voyager (Which I use now) use a different routine, the sync there in EQMOD speak is "Dialog based" What it does is realign the whole pointing model on the one sync point. I can't recall how SGP does it precisely so I will only mention Voyager here. When you request a precise pointing operation, it issues a goto and when that finishes, it plate solves and syncs the mount, if it has missed the target by more than your defined value, it issues another goto (Much smaller now) and then plate solves again, iterating in typically smaller and smaller steps until it hits the threshold for accuracy. Even with my AZEQ6, it generally took no more than three iterations to be within the limits.
I prefer the dialog based sync, while it is cool to see accurate gotos first time after building the pointing model it had to be done every night.
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