I was on the side of leaving it at 60 secs until today.
I was in a large race somewhere in the middle of the pack. I was given a pen at the windward mark (incorrect) but by the time I had dropped the spi and found some room the 60 sec had gone .. the race was ruined ..
So I spent some time running downwind having a beer and thinking about this .. more in relation to the the windward mark. Setting the Spi and dropping takes 30 sec approx .. that leaves 30 ses to do the pen .. so not much time to find a spot to do the 360 and keep clear of the rest of the fleet when you jsut rounded the mark in a close race.
This is why I think there are loads of pens be given by other boats doing 360s. They have no choice or they get another 360, so might as well try and get away with doing a pen in the middle of the fleet.