Beat all 3 heist as fast as you can doing the setup skip glitch or for acts

If you'd somehow skip from the start of the setup itself to the end of, sure. Skipping setups completely by buying them, no.

There's currently no IL for only the finales (sounds like what it'd be without preps and setups^^). If you're looking for Elite Challenges on the finales, check the Elite Leaderboard v3 on GTAF.