Toby,
The guys at T/C know what they are talking about. If you were to take off your scope for cleaning purposes that would be a different story. You could possibly change the point of impact this way, depending on the type of scope mounts that you are using. I've never had problems taking off my scopes and remounting them after cleaning, but with cheap mounts I suppose it's possible. I use Leupolds quick dis-connect mounts and I have had no problems.
In the past, I used the Weaver style rings and bases, but I kept breaking the heads of the screws that hold the rings to the base. With the Weaver style I never experienced impact changes either.
Good Luck and keep it in the 10X
Mac454