Current testing suggests, that the number of faces IS what has measurable influence on things. And not at what I would consider 'normal' counts. Much, much lower.
For illustration purposes, this is the current MkV roadway I'm testing with:
The roadway I created for the sample boat as mentioned earlier, looks like this:
I've since increased the counts in the sample boat model (where I thought it was fine), and I can basically control my FPS via face count at this point. Which again, really makes me think there is perhaps some kind of background calculation going on. Given how the proxied roadways act on the vehicles (ie.. won't hook properly, regardless of autocentering), it seems almost like there is water interaction occurring.
For what it's worth, every square meter of this roadway for the carrier, works, 100% of the time, with no FPS issues. However that is not a ShipX vehicle.
**Also note: If I remove the roadway LOD, there is no performance issues at all. But that is completely against the direction many of us modelers/modders would like to go with the new water features and the assets (you guys dont have..) to support it.