jackie wang

I'm currently using https://github.com/porech/engarde for network aggregation, It's a a open source project can use in raspberry pi os directly rather than openmptcprouter need openwrt or paid solutions like speedify. But it only can provide redundant internet connection, can not add multiple internet's bandwidth together.(need a cloud server)
I really recommend engarde If you don't need very high upload bandwidth.

Wow, I'm making the exact same thing you're making, not using csi camera directly. I use tc358743 to capture 1080p 60fps hdmi input to my raspberry pi and stream it using rtmp rtsp or srt. I'm using openmtcprouter for internet.
https://www.bilibili.com/video/BV1mr4y1m7sL/