I thought I'd share the result of my efforts, I've been asking a few questions about the xbox tuners which I have used and so far since I switched to using VM they have behaved thus far.
My particular configuration means that I schedule a connection to each mux (6 that are of interest to me in the UK), as each mux is pre-tuned, they're always locked and can provide a stream to a client very quickly. I use Emby as a media server and I have a nodejs application I have written to provide a m3u file with the available channels in tvh. I found that I had to create the custom application as I needed to pass the channel number in the m3u as tvheadend sets it to the uuid of the channel which is not usable in emby, I need the channel numbers, so my application simply queries tvheaded and produces a m3u from that data but in a format that allows emby to work correctly.
This is the set of 3 built enclosures, I have 2 tuner boxes which hold the actual tuners, each box can accommodate up to 5 xbox one tuners and the final enclosure is what I call the "electronics" box, this houses two USB-3 4 port hubs, a power supply and connectors for power and a USB-C connector to the outside world.
https://user-images.githubusercontent.com/55795671/133000789-60b35d42-c18e-4df9-8c8a-8cf211a29434.jpg
This is a picture of the inside of the electronics box, a USB-C to USB3-A connector is held with a clamp arrangement, and one hub plugs into the USB-A side, the other hub is plugged into the first hub. The PSU is a 5-36V type and uses a 5.5mm barrel jack. A hole on the side of the enclosure takes the USB plugs from the tuners which are then plugged into the hubs. One of the hubs is flipped of that the power connector breaks out the other side, this makes a huge difference to the cable management.
https://user-images.githubusercontent.com/55795671/133004172-dbe2316b-81c7-416e-a940-e859f4fad723.jpg
This is a insert that is fitted to the inside of the electronics box, it's purpose is just to keep the hubs in position, I designed it as a separate part just so that different hubs could be supported other than the ones I chose.
https://user-images.githubusercontent.com/55795671/133004171-e015eb2c-8bef-4f30-9433-58805924ac02.jpg
This is the 3D model of the enclosure showing how the USB connector and insert all fir together.
https://user-images.githubusercontent.com/55795671/133004176-bb535cc6-9b31-4ed3-9846-9302aa783d5f.jpg
The clamp part, the USB-A to USB-C adaptor can be seen, there are 2 parts to the clamp which uses threaded inserts, the screws are tightened which hold the coupler firmly in place and then the assembly is push fitted into the main enclosure, it is designed to fit to the top of the case so there is no chance of it becoming loose. There's a small channel which allow the power supply cables to go through to the PSU, as I mentioned there is no clearance above this part so the channel is required to get the cables over to the PSU board.
https://user-images.githubusercontent.com/55795671/133004183-198cdf4f-1a98-4333-bda8-c2326712adba.jpg
This shows the completed assembly. The actual coupler sticks out a few mm so that when it is installed, it is flush with the case.
https://user-images.githubusercontent.com/55795671/133004185-3209ec7d-b2e1-4bc2-98ed-7e05ad7ac1e4.jpg
A picture showing the DC jack, coupler assembly and power supply in place. The channel for the power supply wires can be seen at the top.
https://user-images.githubusercontent.com/55795671/133004168-cd350c3e-cb05-4597-9696-793290106cd2.jpg
A picture showing the coupler assembly and insert for the hubs.
https://user-images.githubusercontent.com/55795671/133004166-f3b20400-5495-4203-b0f7-0c75c6423c8d.jpg
Next is the base for the tuner enclosure, each channel in this is the correct size to hold an xbox-one tuner, a lip at the front prevents the tuner from slipping out.
https://user-images.githubusercontent.com/55795671/133004180-a5be49f2-b912-40e7-993b-60510635fab3.jpg
Here is the enclosure with the tuners fitted. In this case, there are 3 tuners and 2 "blanks". I need 6 tuners, so I split them evenly across both boxes.
https://user-images.githubusercontent.com/55795671/133004182-ad52cce5-ea14-435c-bc45-2620bc8bfac1.jpg
Here is the very simply blank part.
https://user-images.githubusercontent.com/55795671/133004179-ea2ece30-e301-40da-afb3-3dfdbcf2bc9c.jpg
And finally, I used rg316 cable to create the cables which run from the distributor to each tuner, rg316 does look very neat but it took a few hours to produce the cables as I didn't have the correct stripping tool so had to manually strip each cable which was time consuming to ensure that I didn't make any mistakes while stripping the cable.