I hope you get your mount issues sorted soon. Yes I too was very surprised to see so much detail in the Ha subs at only 20 seconds. I had a long night of trying to sort out all kinds of problems with the centering functions of SGP. In the end, I only had a couple of hours left before the morning twilight so I just got 16x20 seconds of Ha (pictured above) and 20 x 10 seconds of R, G and B.
The Ha RGB mix is
here