I've made two separate stream bags using Belabox. One is more intense for my birding and rocket launch coverage streams where I need HDMI switching capabilities for multiple camera inputs and consistent audio quality. I've also made a "lite" version for cycling, metal detecting, and just when I don't need the ATEM. I forever searched for the best wireless camera solution that allowed RTMP into the Belabox and also a wireless mic input to the camera. DJI Action 4 and DJI Mic2 finally allowed this and quality is good enough for me.
Overview of the stream setup for HDMI switching
Overview of the more wireless 'lite' stream setup
The Belabox setup uses a Jetson Nano to act as an encoder and network bonder. Most importantly it uses SRT instead of RTMP. There is much better info out there than what I can provide here. RationalIRL (the Belabox dev) also has a great discord community.
Why Nano/Belabox over LiveU Solo?
If the technical aspect of the setup concerns you, Rational has made it super easy to get up and running if you can flash an SD card. Sometimes you have some messing around to do related to power issues and modems, but his Discord is very helpful. If you stick to the recommended equipment list and short cables, you should not have issues. LiveU is more plug and play if you have an RTMP endpoint.
Summary of specific Belabox items I use:
Encoder: Jetson Nano 2GB running Belabox
Capture Card: Elgato Cam Link 4K
USB Hub: iDsonix 4-port 5V/2A
USB-A to Type-C Cable: JXMOX 0.8ft 3 Pack
USB-A to Type-C Cable: Etguuds 2-Pack, 1ft
Metal Case: Jetson Nano Metal Case/Enclosure
Fan: 5V Cooling Fan
USB Sound Card (if not using ATEM): CableCreation USB Audio Adapter
Battery: Charmast 23800mAh 20W PD* (powers Nano, USB fans, and shoulder cam from same battery with no issue)
WiFi Adapter: TP-Link TL-WN725N
Organizer: Cocoon GRID-IT
For a more complete gear checklist, please see the gear page.