So if you get there at the last minute when your flight is about to close, you can go to that separate desk and skip the queue... that is what I tend to do. Thus, you would be totally fine getting there at 5:30 or even a bit later.
Just a warning on that. I've had checked in baggage got lost in transit twice. It happens when you just get to the desk before closing and basically you make the flight but your luggage doesn't.
This happened to me in 2 different years, 2 different flights and 2 different airlines under 2 different circumstances but the common thread was a delay airport side:
(a) Frankfurt to Leipzig with Luftansa
(b) Dublin to London with Aer Lingus.
In both cases, I was at Dublin airport on time with plenty of check in time.
But in the first instance the Dublin to Frankfurt flight got delayed leaving Dublin (check in went smooth but it was weather that caused the delay) thus almost missed the internal transfer to Leipzig.
In the second instance last summer during the delay's on flights leaving Dublin airport due to the problems with air traffic control outages. My flight was delayed an hour and half, so when I went to check in the hour and half later to which I thought was the time for my flight to check in as per the screens, the ground staff bumped up my flight to the earlier again but also delayed flight that was at that time closing.
In hindsight I should have stayed with the original flight no as it was only about 3/4 hr later in the end.
Sadly the outcome was the same, my luggage got delayed for 1 day in the first as it was left in Frankfurt, where as it was over 48 hrs the second time as the luggage didn't even depart Dublin and it took ages for the staff to realise this.
Both times I was only going away for about 3-4 days.
So best to not just nearly miss the flight if having checked in luggage no matter what airline you are on. Other times I've flown and checked in with plenty of time, the luggage got onto the flight as per normal.
That said, flying with Ryanair tomorrow as well! Different flight though. Right back to packing.
