30 seconds (black) | 35 seconds (white)
mate in 3 forced to white| mate in four forced to white.
40 seconds (white) | 35 seconds (black)
both guys with white will be sitting, and the guy who has 35 seconds will only start moving when their time ticks down to the last seconds, hoping that something happens in the mad time scramble.
30 minutes (black) | 39 minutes 45 seconds (white)
mate in 3 to white | mate in 3 to white
40 minutes (white) | 31 minute 15seconds (black)
again, guy who is getting mated and has less time should sit, forcing the other guy to sit too. But now they both will have to sit for ~40minutes to get in that same time scramble situation.
edit: i just can't format this sh-it properly, hopefully it will be understandable.
edit2: it's not exactly what smilingbill was talking about, but still works as an argument for why longer time controls wouldn't be good for bug.