I'm a little surprised you seem to be having so much of an issue with this cable. I use WF100 for all my own work. Here's a bit of it I have lying around the office. This piece has one of my screw-on connectors attached, but I use the same compression plugs as you for my outdoor and loft work and it doesn't change the behaviour of the cable. It'll take a bend quite easily.
Obviously it's going to be stiffer than the WF65-size twin shotgun that Sky use because it's thicker and includes a proper copper foil shield rather than Mylar which is aluminium-coated plastic, but I wouldn't call it especially stiff. It's not like WF125 for example.
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I know that the weight and leverage of some cables can be an issue for weaker grid modules. I've come across situations where Cat5e network cable has pulled out weaker modules in a Euro face plate, so I can imagine that the same might be true with RG6-sized coax, especially if equipment is pushed up against a wall which then leads to a bit of leverage pressure on the cable.
If you're still struggling with the fly leads I can make up some single run WF65-sized coax with crimp connectors for you. That's going to be about the most flexible you'll get in a standard foil/braid shielded coax without going to flat ribbon or sacrificing the foil shield.
The other alternative is some mad double braid shielded BBC coax I have, but it's a hell of a lot heavier for only a marginal increase in flexibility. The density of the double braid shielding won't completely compensate for the loss of the foil shield, but it's never come up as a problem in the OB rigs where this type of cable was used.
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