I got up early this morning to have another go at M81/M82, and shot about an hour of 8 second frames. I'm not so happy with the telescope for RGB photographic use, looking at the stars, but this is admittedly with the stars and galaxies sharing the same stretch. If I separated the stars into a separate stretch I think it would look much nicer. Also the image is wierdly colorless, so not entirely sure I didn't mess up at some point in the processing. I'm sleep deprived and liable to err!
The result is very noisy - but I only had an hour of clear sky before dawn twilight, and no further nights at my dark sky location, so no possibility to add more data.
Regarding the stars, focus is extremely critical with this f5.5 telescope, so I am ordering a Bahtinov mask to get that perfect.
Aside from star bloating, the telescope behaved nicely on my AZ-GTI so I expect it will give nice results (to my eye) with a duo band filter, or even in RGB with more careful processing.