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Star alignment and polar alignment are conceptually different things. One affects goto accuracy, the other tracking accuracy. One aligns the telescope axis with SynScan's computer model of the sky, the other aligns the RA axis with the axis of Earth's rotation, so that tracking can be performed via rotation in RA alone. They are independent, meaning you can get good goto performance on a non polar aligned mount, and good tracking on a non goto aligned one.
The shortcut you mention in your procedure is based on the idea that if on power-up the mount is in its home position (counterweight bar at lowest position and OTA parallel to RA axis) then a polar aligned mount should be able to perform gotos without star alignment. This allows you to detect and correct gross polar alignment errors before commencing the actual star alignment, saving time later on.
For this to work the mount must be close to its home position, and date, time & location must have been entered correctly. Given this, slewing to the first alignment star will get you very close with a polar aligned mount, or show you the polar alignment error otherwise. You can correct the bulk of that error through physical adjustments before pressing enter. This can be useful if you have no reliable way of determining the south direction and are way off. It can reduce the number of polar alignment iterations later on.
This is meant to be a time saving shortcut, and is not required. It is no substitute for proper polar alignment. After 2- or 3-star alignment the polar alignment error will be displayed. It needs to be diminished via the SynScan PA routine (or drift alignment if you prefer). Keep in mind that every mechanical adjustment to the mount as part of polar alignment invalidates the pointing model, so the star alignment has to be redone after each polar alignment iteration, in order to obtain a new reading of the remaining polar alignment error.
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