Yep,
It will work but is a very hard way to do it.

I use a new series Gtech pro RR and they are so close its not funny.

I did some runs on a friends car 3 weekends ago while doing some base level tuning and then we did 37 power runs at Melbourne performance centres dyno last weeknd and the difference was 2% between Gtech estimate and dyno RW Kw's.

Its an interesting and challenging mental excercise if you have the time :)