Is this the equivalent of the Flying Banana for branches, or something else?
Well,
IETs▸ (a fraction of them anyway) have:
Pantograph Camera System
Unattended Overhead Line Measurement System (UOMS) (provison for future fit only)
Unattended Track Geometry Measurement System (UGMS).
So in the sense that there are branches IETs won't venture down, maybe it answers more to that.