Theoretically the magazine cut-out weakens the receiver and the requisite hole in the stock compromises the bedding. In practice I have several sporters that routinely shoot better scores than my heavy rifles even with the small scopes and no tuners.
I'll acknowledge that hanging a tuner on the end of a big barrel with those sporter actions may cause the weakened action and bedding to become a factor. My bet is a 3" forearm and bigger scope on a repeater action with sporter profile barrel, sans tuner, will still be more than competitive.
From another perspective, there are a lot of Remington 37's with magazine cutout still showing up at the upper levels.
As Bill B says, the sporter Turbo actions are in short supply and you could probably get a good trade.