I should have posted this a while back but I figured others had found even better solutions.
Unlike many LR4 installations, my dust collection MUST come from the side. My ceiling is 12’ high but my central dust collection is under my raised floor, so, together with the need for pretty high static pressure for the router, a dedicated shop vac is the only practical solution.
The problem that I had is that the dust hose and the cabling are not actually aligned for part of the path, so I initially had lots of problems with wiring getting caught or it causing the vac hose to lift out of the tray. But, in the end my modifications work pretty well (>90% without issues.)
Here are some pictures.
Note that the cabling and drag chain are on a separate path almost immediately…they are never attached to the vac hose. This allows nearly complete independence of the two motions.
This shows a slightly different angle. (Please ignore the clutter!) You can also see the magnetic disconnect for the vac house as well as the LCD display for the SKR 1.3 control board that rides on the end of the LR4.
Front view. It may be possible to see the “core extender” that I added to keep the two paths separate.
The extender does two things. First it provides a location to attach the drag chain so that the cables can be fed into it. Second, it extends beyond the end of the core so that the vac hose has a couple of inches more surface to which it can be attached.
And, a closeup of the extender:
The extender is my own design and is just cable tied to the core. There are some tweaks that could be done, but so far have not been critically needed.
Finally, I have slightly modified the braces that hold the vac hose in place. They also provide a location to attach the drag chain.
Hopefully this is fairly clear without being unnecessarily detailed. At some point, I’ll try to post the ”extender" design on Printables, but that may take a while. The design is in Onshape, so if someone needs it, I can post a link here or something. (I also plan to post a video but that will be even longer… 
)