Thanks for taking the time to answer.
To be frank, I'm even more confused :(
SGP seems to compute the time at which the meridian flip would theoretically occur. I let SGP manage the flip by itself. I don't want to interfere with this - just want to ensure that the current frame is finished before the flip. I thus changed the setting in SGP to wait for 10 more minutes,
But what should I do in APCC? Leave everything empty in APCC and the AP ASCOM driver? I noticed that setting values there to what I believed were correct for what I wanted to achieve, ruined my session last night: the mount has stopped in a weird position.
I wish a recommended approach / clear directions were documented somewhere.