The ideal situation would occur if the promoter can immediately publish after the weigh-ins an estimate of the starting time of each event and post it where the majority of the participants and ticket buyers can see it.
This, of course, is easier said than done; but it would give the ticket buyers an estimated time when the event they want to see would start.
There is a big turn-over within the audience due to this increase number of events (fans stay until the event they are interested in is over and those empty seats get full again), but I don't have any stats regarding audience turn-over.
It would be ideal for all concerned if estimated event times can be posted and adhered to, but as I said above.... that's easier said than done unless the contest was extended to a three day period.