If you have some installations where the length of the cable run is suspected to be perhaps a little (too) long, it would be nice to measure the length of the cable. However, meter sticks won't work when the wire is pulled, so a Time Domain Reflectometer (TDR) can come in handy? Unfortunately without a known 50+ ft length of this cable, it can be hard to guess/measure what the NVP value of cable is, and therefore impossible to measure with a TDR.
Would anyone have some typical average values for the Lutron cables?

18/2 + Belden 9461
16/2 + Belden 9461
third-party cables

Perhaps other people have already done sample measurements and/or the factory has some data to share? If enough people can share their data, then we should be able to get a good average for each cable type, and then make useful measurements?