A simple 50/50 test, one normal layout and one interrupt set to 1800 seconds per hour will show that the interrupt regularly overplays, sometimes as far as 2100 seconds.
I think this is due to the left over time after we've done our "picks" - normal pick/interrupt pick are unlikely to be integers and therefore there will always be time at the end of the loop.
A simple 50/50 test, one normal layout and one interrupt set to 1800 seconds per hour will show that the interrupt regularly overplays, sometimes as far as 2100 seconds.
I think this is due to the left over time after we've done our "picks" - normal pick/interrupt pick are unlikely to be integers and therefore there will always be time at the end of the loop.