Regrading "useful data" from your relative compression test could I ask if this is to determine the offending cylinder?
If so, then the following Case-Study from Ben describes the approach taken for a Parallel Twin engine.
Whilst this is not your V Twin, the techniques describe the application of PicoScope and a current clamp to determine cranking effort (relative to compression) via the starter motor current draw.
Introducing a second channel to capture the ignition event of cylinder 1 will help identify each cylinder