Topic: Need advice: HDMI audio to FFMpeg for UDP stream

Hello, I'm looking for away to to several things, all which I think I can figure out but I'd like to know if these are possible:

1. Capture the audio in and send it to FFMPEG? I'm currently doing this with a Raspberry Pi 3b+ but I'm forced to use a USB audio interface which is adding latency. I've been able to get the latency down to about 1 second via HTML using: being able to do this directly within this device would elmiated the need for 2 devices and possibly reduce the latency. I don't believe the audio is sent through the chip so this may not be possible. This just allows users to easily access a simple web interface on their phones to listen to the audio privately.

2. Can I introduce latency into the video to make up for the audio latency?

Any constructive advice is appreciated.

I'm also concerned about production, I would need hundreds of these if I can do the above, will NetTV2 be available soon?