I am relatively new to astrophotography and EKOS and mainly use the standard PA assistant so I will help the best I can and hopefuly somebody wuth more experience will jump in.

In my experience, an error of half an arcmin should be decent for up to 30secs or even 1min unguided subs.

Considering that the earth spins at 15 arcsecs per sec at the celestial equator, so having a drift of 0.08 arcsecs per sec (5arcsec per min) seems very decent!

I use a 600mm SW 80ED with a ZWO 1600, that combination results in ~2arcsecs per pixel. Having 5arcsecs per min drift would mean that for a 1min sub , there would be a 2.5 pixels drift. For an unguided setup, I think I could live with that. If you cant, then indeed that PA error needs to be reduced.

The bigger problem is that for a long imaging session, the drift would cause issues with the composition. Using the same maths, after 1 hour, I would be 150pixels off... The only solution I can see to do is either further improve PA accuracy, do plate solving every now and then or use guiding.

Regards

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