I decided on a Score format because of Covid-19 and it went very well.  The only contact the school had with anyone else was when the teacher collected the Teachers Bag (maps and SI cards) and also when the teacher returned all the SI cards to me to be counted.  SI cards were all ‘Cleared’ by me beforehand.  Teachers ‘Started’ their own students from their bus or wherever they congregated.  No need for Startlists or Start boxes.  They started them all off within about 10-15 mins.  Then they all spread out in all directions looking for controls.
30 controls, each with a score (10 pts; 20 pts; 30 pts) allocated to them.  A Time Limit of 45 mins to get as many controls as they could.  A penalty of 10 pts deducted for every minute they returned over the time limit.  I would think that a Time Limit of 60 mins would be better for your schools cos some of them can walk very slowly and you’d want them to get a decent amount of controls.  It doesn’t matter that the faster ones come back much quicker.
Mary Healy