By “dry track” i assume you mean DI guitar with no Axe-Fx processing? You’d want to run that back through the Axe to capture an reamp with just an amp block and no cab block, then you’d apply Cab-Lab plugin to that track. If by “dry track” you mean a tap of the amp block signs before a Cab block, you could apply the Cab-Lab plugin to that track, but then that would not be suitable for a reamp. The long and the short of it is how ever you chose to capture you’ll want to apply the Cab-Lab plugin to a track that’s recorded without any Cab block processing from the Axe-Fx.