Yeah, a hold will do the same thing every time.
I usually take all the holds out to create solos (and save that as a separate SGU).

Here is a "trick"... or "something to try"...

When a solo is too busy and you want something that holds notes a little longer...

...look for a similar sounding solo that is HALF the tempo of your song.
When you load that RealTrack, select "Half-Time" - so that is plays at its original tempo and not twice what it should.
You will get a much smoother, more musical solo guy.
And you might find some good long notes to use where you need them...