As mentioned already, if you already use a guidescope or even OAG, SharpCap. No need for them to be orthogonal at all. MUCH easier than the Synscan PA too.
Pole master adds more cables, more (terrible) software, incorrect instructions for Southern Hemisphere, and more cost. It’ll be about 40 years of SharpCap annual renewals before you catch up to the Polemaster cost