The intent behind the "You cannot be both prone and behind cover" line is that you cannot claim the prone modifier (-1) while behind cover. If you're behind cover, full or partial, the cover rules apply, and there is no -1 modifier for also being prone.
I see. That definitely clears up the wording. Thanks.
And yes, the intent is also that if suppressed while behind partial cover, you will drop to a prone position and thus also go into full cover.
Fine with that. It was kind of obvious but worth clarifying as the wording of "cannot be both prone and behind cover" was a bit odd.
You can seek cover in your hex even when prone.
Ah ha! Now this is important. So are you saying that if I'm prone behind a low wall and thus out of sight and in full cover, I can seek partial cover over that wall without first doing a fast action to "get up". It does sound like that's what you're saying - i.e. seek cover includes any required change in stance?
I hope that clears it up!
90% there, probably 100% if I interpreted the point about seeking cover whilst prone correctly.