To the best of my recollection, there hasn’t been much talk of turbo/supercharged engines that have been grooved, Simon, so you might be waiting a while.
Of course, you could go against your mechanic’s recommendation and try it on your vehicle to see what happens. It could make a difference, and it could be in a good way. We’re trailblazers around here, remember. I hope you choose to bravely take the chance, and report back here with positive results.