I agree with you, FBW, there is no counter to some-one being on 24/7 refreshing until slots appear (well, there are the logs which Sami can check and chastise anyone excessively doing so).
I'm just a bit cynical about this issue : whatever way its done, some-one (who didnt get a slot) will demand a change to the system where, surprise surprise, they will get a slot : and then the person who now doesnt get the slot will, surprise surprise, demand a further change which, surprise, surprise, has the totally unexpected outcome of... they get a slot.
We could have Sami working 24/7 re-coding this every two days and guess what : the ones who cant get a slot will keep on wanting more changes to ensure they... get a slot.
The only solution is to offer as many slots as people want : then they will complain about air traffic delays instead cos of 400 planes trying to take-off and 400 planes trying to land every minute...
I'm going to bed... cue : appearance of much sought-after 6.00 slot 5 mins after I start snoring...... its just soooooooooo unfair!