Thanks a lot Max, great. Last night I tweaked a few settings and also tried out a longer FL guider, and got much improved results (screenshots below for folks interested). It might be that the seeing was just better, or my polar alignment is not great (this is a rooftop location too, and so not on solid ground). However, the longer FL made a huge difference - down to below 1" now - and I ended up after experimentation with aggr=0.8 and intr=0.2 but will try your settings tonight as well. Initially I went with 1s exposures binned 2x2 but then went back to non-binned, as you do. The exposure length seems to make a difference with 0.5s being a bit noisier but guides better, although not completely obvious (the first screendshot, where the yellow SNR line drops/steps down marking the switch between 1s and 0.5s):