The RTSP plug-in source code is here:
You may be able to recompile it for the X using Android Studio.
If you connect the X to a small computer (like a Jetson Nano) with a USB cable, you can use ffmeg on the small computer to get the stream to your local RTMP server.
For example:
ffmpeg -f lavfi -i anullsrc -f v4l2 -s 1920x960 -r 10 -i /dev/video2 \
-vcodec libx264 -pix_fmt yuv420p \
-b:v 2500k \
-codec:a libmp3lame -ar 44100 -b:a 11025 -bufsize 512k \
-f flv rtmp://a.rtmp.youtube.com/live2/$SECRET_KEY
A few years ago, we used this to improve performance.
Paul Gullet saw a doubling of the framerate.