I have a similar practical real problem.

A vertical 120 ft working 75 ohm coax line hung from the top.

The soft foamed dielectric MAY be crushed under the cable's own weight
10 ft from the top end.

If it is I must change the hanging system.

ASSUMPTIONS
- the dielectric is crushed to 1/2 the original thickness over 2
inches length 10 ft from the far end
- I can put a good quality non-reflecting 75 ohm load at the far end.

QUESTION
Can I expect such a defect to generate a detectable reflection at
2GHz?