Of course you can. While transmitting CQ on Slice 1, you can search on Slice 2 without transmitting TX to Slice 2.
You can use the Alt+Up/Alt+Dn hotkeys to move through the spots of another slice without transferring focus to it.
You can turn on CQ+Auto on Slice 1, go to the Slice 2 window and search there.
It all works. Your job is to customize the audio (volume, left/right) for yourself to ensure you are as comfortable as possible. Once you have customized your audio, save these settings to your profile to use them in the future.