LC76 reading out AGC [dB] level

How can I read current AGC level in dB on LC76?

The goal is have an idea of signal level even if no satellites show up.
(high AGC → low signal)

This was very easy in ublox via MON-HW ubx message.

I can’t find an answer to your question for the LC76F or the LC76G; but while you wait for an answer from Quectel, I’d recommend you reply back with a picture of the module and the current firmware version as the answer might depend on which chip you have in your module.

or Signal to Noise ratio, or C/No level, before seeing any satellites.

It’s LC76GPAMD
image

but something universal message would be nice across AG33* chipsets.

I looked through all of the Airoha commands I’ve come across across vendors, but I can’t find anything that gives AGC values or any additional signal strength info past what is provided in the standard NMEA messages.

I hope a Quectel employee has better news for you.