Using memory (a dangerous activity), I used to configure and scan Dish #1 (1.2m motorized) using Tuner A. I would then configure and scan Dish #2 (1m fixed) using Tuner B. Once all the satellites were scanned in on each dish, then I could use the Signalfinder feature to look at the signal quality on each dish for a given transponder for comparison. Using Signalfinder, you can switch back and forth quickly between Tuner A and Tuner B to compare.
There is another feature that allows you to program your priority for which dish to use when a signal is available from more than one dish. You'll have to dig for that since I don't have the user interface available anymore. This could, for example, give priority for a fixed dish if you wanted to record something from it so you could keep your other dish available to tune other transponders or satellites.