The only time I take advantage of niceholes is at MUP street crossings, and only under the following conditions:
1) There is either no other traffic, or drivers in both directions have stopped (happens pretty frequently here).
2) at 3 or 4 way stops. I always stop and put my foot down, or stop and make an obvious sign of looking both directions when I'm in my velo. If they STILL wave me through after waiting an extra 3-4 seconds, I'll go if condition 1 is satisfied.