What about changing the massed start to individual starts with a 2 second gap between cars. The pole sitter would be right on the start-finish line so would cross at fairly slow speed, but the cars further back would cross at higher speed, so the field would bunch up on the first lap. But, the pole-sitter would need to beat the car behind by more than 2 seconds to be classified the winner, so he would need to drive quickly instead of just cruising around saving his tyres. Same for the guy in second, he would need to beat the guy in third by at least two seconds, and so on.
Also, mandate two tyre changes, with the cars having to finish the race on the same compound as they started on, but with a different compound for the middle stint. They would therefore finish on the hypersoft qualifying tyre, but timing that final pitstop would be the crucial strategy call.