If you obtain an overlap after the two boatlengths zone (through speed differences or a tack or a gybe), you'd better be ready to bail-out or be sure the boat in-front is gonna stuff his rounding and leave a gaping hole for you to round in.

Think ahead when coming into a rounding, particularly in cats because they are so fast. Assess early what you're likely-hood of obtaining an overlap is. If it is unlikely, back off and do a fast, tactical rounding and put pressure on the boat in front to nail its rounding. If it doesn't, you will have a very nice cover on them, stopping them from tacking. Just be sure not to get lee-bowed.