I think my focusing is not too good, judging from the FWHM values in my long exposure images, which is about 4-5". I use a 10" Newton with a ccd yielding 1.3 "/pixel. The guide module report about 1" corrections.
When focusing I can get down to about 1.75-2 HFR in ekos autofocus. Is this good enough/to be expected? What values do you guys get for sharp focus?
The optimal focus position also seems really flat, so I am suspecting that something is off in my system, but where to look is the question....
Hard to say. Your numbers could be erroneous or you could be under bad seeing. You can try your best at manually focussing and comparing results. A bahtinov mask can also show you how good the focus/autofocus was.
You seem confident in your guiding performance, but if not double check that the accuracy figgures are being accurately calculated properly with an accurate focal length set.
INDI/KStars on Raspberry Pi 4, 4gb
Raspbian Buster with AstroPi3 script configuration
Skywatcher HEQ5 Pro Mount
Canon 600D Camera
Orion SSAG/ASI120mm @280mm Guide Scope
Adafruit Motor Hat shield
Adafruit GPS Module
Generic Bluetooth Joystick.
Startech 7 port powered USB Hub.