Native SGP interface to SmartLock?

DesertSky,
Given the way the ONAG is set up and the way it works best filter offsets are almost always required if the filters are not parfocal. Check out the documentation. https://www.innovationsforesight.com/education/on-axis-guider-onag/
To be sure some might choose to put the filters ahead of the ONAG but they would likely lose a lot of signal for the guide camera. Best--Tim