Running backs -- continuous line or two part?

[Brion Toss]

Hello,
What your rigger is suggesting will work, but I'm not entranced with the logic, and there are problems specific to a two-part configuration.
So where to start... well, first the possibility of damage. If you have a one-piece runner, and part of it gets damaged, you can always turn it into a two-part runner; starting with two just means two extra splices, plus that problematic thimble, and a runner that is more awkward to handle. And what is going to damage these things? HM covers are very tough, and can be replaced or mended if need be, with no damage to the structural part. You might want to leave the cover on any parts that might see chafe. Cheap insurance.
We leave the cover on all the way, usually, until it enters the single-braid tail down near the block. Then we strip the cover off, leaving an HM tail long enough to get onto the winch before the load comes on. The rest of the single braid is hollow. Single braid is fat, comfy, and easy to handle.
Fair leads,
Brion Toss