windbreaker;291569 wroteThe more top heavy prize structure of this events are, it makes +chipEV decisions approach +$EV decisions. As a result, you should make more +chipEV decisions in this spot, since 3rd/4th/5th place essentially pay relatively small compared to 1st and 2nd.
You're right that the more top heavy a prize structure is, the closer to cEV your decisions become, but 40% of the field getting ~100% of the prizes isn't exactly top heavy. I did some quick calculations, pretty sure they're accurate but there's some chance I made a mistake because I rarely do ICM calcs like this, but this is what I found:
He needs to be shoving more than 66+,AJs+,KJs+,QJs,AJo+,KQo (9.5%) for us to call after we 3-bet as opposed to the 99+,AQ+ (5.1%) that makes it +cEV. 99+, AQ+ shows a slight profit in terms of chips, but we burn ~$800 by calling. I'm not positive of his shoving range here but I highly doubt he's 4-betting that wide without any dynamic.