Not really ....
When you do a Slimline set up ... you do the Tilt (skew) and the Elevation while on the ground ... then place the dish on the mount and adjust the Left/Right once its up .... with fine tuning adjustments on the rest once you have signal ...
So, taking the dish off the roof, but not making any changes on the dish, should allow you to place the dish in a close location and only have to do the Left / Right to find signal (as long as your MOUNT is Plumb ...
If you notice, you can move to a surrounding city and the Elevation and Skew may not change ...
I just moved a dish at the lake a few weeks ago off of the house to out front towards the lake (on the house is being blocked by the trees now) took it down and was able to easily point it once out at the lake without making any changes on the dish other than Left / Right.