Asymmetric upside is only really useful if the EV is positive.

Bets "on the inside" in roulette have asymmetric upside, they pay out 35:1.

The problem is that the chance of winning is 37:1 on an American wheel.

This means that the EV is negative: do it enough times and you will lose money.

You should constrain your search to positive EV gambles.