Hello guys, I've made this custom firmware based on the original 1.2.13 firmware for Z22L.
I've followed this guide
I've modified the bitrate as per excel file that you can download on the video comments.
1080p50 35/25/20 Mbps
1080p25 25/20/15 Mbps
and so on...
It works great on my Yi.
Try it...