j.fernwright - trying to get my head around this one and how you’re intending to split the edges. Have you got an example to demonstrate. I can’t help think the insert edge loop does this.
Bevel edge splits edges, slice curve, slice circle, and slice square all will split loops and rings, just choose the one that most closely resembles the configuration you need. Remember that the slice curve line can be bent and curved. But also remember, no Ngons, so it will insert extra edges to force quads.
Most of the time it’s just a matter of thinking about things a different way. Instead of getting hung up thinking about how you can split a loop, see if there’s an opportunity to inset a region, or an opportunity to use the * existing * Zbrush ability to insert an edge loop somewhere that geometry has been moved while the rest of the mesh is hidden with the Edge loop command in the tool> geometry> edge loops menu.