For me, it depends what kind of solo I´m learning. If it´s a slower emotional solo than I learn it how it is but if it´s a fast solo like Malmsteen our so than I throw a lot of my own stuff because I find it impossible to figure out all tones when the solo is like speed of light and my theory is, as long it sounds fast as orginal and a bit close, it´s ok. But as I said earlier, learning slower solos and famous solos like Stairway, Final Countdown, Guns, Metallica... than it´s important to learn it as close as possible.

But if you just listen to Yngwies solos, honestly, can you somtimes hear the diference betwen solos in diferent song? Especially faster parts.