[TowerTalk] Inner conductor migration in Heliax(TM)

[David Aslin G3WGN]

Hi all,
Looking for the TT brains trust to help me out with this issue:
I have two drums of LDF4-50 and one of LDF5-50 which have been stored on their sides for around 10 years.  This disobeys one of the prime directives, since Andrew/Commscope say they MUST be stored with the drums vertical.  My understanding is that the horizontal storage may lead to inner conductor migration.
QUESTIONS: How can I determine whether migration has occurred; if so to what extent; and what extent should cause me to avoid using the cable for the 50m/165ft+ runs to my HF towers?

Of course, if there is gross migration, a continuity check from inner to outer would reveal a short, but would a TDR or other method reveal performance degradation from lesser amounts of migration?
73, David G3WGN  M6O