well, if its something like QQxx vs [Th][Ac][9c] on a [Jh][7c] board is 58% to win the hand.

However, for someone (heads up) to be a favorite, they need to have a HUGE draw like this wrap straight flush draw and backdoor flush draw.

If you are against 2 opponents and one has the flush draw while one has the wrap straight draw and one has the flush draw and a gutshot, the odds change.

The set is then 40% to win, the wrap draw is 24% to win and the flush/gutshot draw is 30% to win (6% to tie with wrap draw). So, now the set has more than its share of the equity in the hand and can possible get 2 people's stacks in which definitely makes it +EV.

Even when its heads up verse the wrap straight flush draw, there may be enough money in the pot to make it neutral EV to push and since people don't often have this wrap, it is +EV to push anyway.

In a short stack game it's basically always correct to push top set on any board as long as a made straight or flush isn't possible. These gigantic wrap flush draws that break sets are incredibly rare and in most cases the set will be 60%+ against most draws. Even the most monumental draws on the flop are 60-40 favourite over the set. Unless the money's collosally deep you should just keep raising until you're at the felt, generally.