I know members that use it when single pole fishing, Spider Rigging, and when Pushing jigs.
The main "plus" that I can see with using it when Spider Rigging is being able to "scan" ahead (with a slight turn of the transducer) in order to see the cover prior to getting to it, either to avoid running all your lines into it or to check and see if there's even any fish on it worth your time to fish it. Since Spider Rigging is a relatively slow movement method, you'd have time enough to scan the cover prior to your baits reaching it ... but, as far as "watching each rod to see the fish bite", not gonna happen. You're going to have to depend on watching rod tips in that scenario.
You "can" get a Garmin unit, like say a 93sv, with the transducer (SI/DI) and hook the Livescope system up to that & have split screen capability. The downside to that setup is the same as with any split screen system ... each section of screen is small & may be hard to see much in the way of detail. (not to mention that the 93sv transducer adds nearly $200 to the overall cost of that system combination)
Many simply use the Garmin unit of their choice to run the Livescope ... and a separate unit (with GPS mapping) to add waypoints as they are found or use those previously found to plan their routes. Some have the whole screen on map, others may have a split screen of map & sonar (2d/DI/SI ... depending on the capabilities of that particular unit).
I don't Spider Rig, but I know a local guide that just recently added Livescope and his main fishing method IS Spider Rigging .... if that tells you anything.