Hi guys, sorry for the late response. I just read this thread and as as i am using the SGP and the ASIAir Pro as well, i thought about sharing my experience. I am able to polar align and do pretty good guiding using this setup.
What i am missing in this thread is what you actually connect to the SGP’s ST4 port. I have my ASI 1600MM Pro connected to the ASIAir Pro’s USB3 port. My ASI 290MM Mini guide camera is connected to the 1600MM via USB2 (for power) and (!) directly to the SGP’s ST4 port.
When i start a session, i disable the mount in the ASIAir’s settings (touch the telescope icon, then switch off the toggle button in the upper right). For me it does not matter if the SGP is turned on or off during PA. Usually i keep it on to prevent elongated stars. After focusing i start ASIAir’s PA routine. As Chen pointed out (in another thread) i do not start at 0”. In my case it’s because a roof is in the way to Polaris. I rotate about 15-20 degrees to the east. After initial plate solving in PA i turn the RA axis manually about 60 degrees to the west and hit “continue”. From there it’s about turning the knobs until total error is below 2 arcsecs. When PA is done, i choose my target by manually changing RA and Dec, enable the mount in ASIAir’s settings, go to the guiding view, start by touching the “loop” icon and then select my guide star. When the mount did its calibration (which never failed on me) i am able to start imaging.
Hope this helps to solve your problems. Good luck and clear skies!
: i use the latest ASIAir app and firmware (v1.5).