The only way the Tour is going to be viable on truly heavy is if you're going to play dead straight up the lane (no belly), and there is a ton of friction down the lane. In a case like that, I could possibly see it because the mild break point of the IQ Tour could possibly keep the ball from going sideways down the lane. Still, I doubt there will be many cases where that is a bowler's best option. That being said, I would look into Storm/Roto's numerous other true heavy condition balls to fill that slot.
To give you some perspective, the IQ Tour solid is the 4th-strongest ball I carry. It is behind my Sync, Zero Gravity, and Lucid (2000-grit matte). For me, the Tour is the "benchmark" ball in my arsenal. It rolls smoothly and evenly to help me figure out what the lanes are doing.