Greetings. I’m Lance, the creator of the Lefebure NTRIP client. I’ve seen several e-mails about the 12 satellite thing in GGA sentences, so I thought I’d chime in. Most NTRIP casters want a GGA, so that’s what I use on the NTRIP client as well.
Suggestion: on your receiver, have the option for two different GGA sentences. One is what you have now, a strict NMEA compliant message. The other being a GGA with a few tweaks - satellite count can go above 12, lat/lon precision increases from 4 to 7 digits after the decimal place, and altitude precision increases from 2 to 3 digits after the decimal place.
The solution above is what NovAtel does and they call the messages GGA and GGALONG in the configuration, even though both are output as a “GPGGA”. I can’t recall ever seeing a piece of software that requires the strict NMEA standard, but it’s there if someone needs it. I know Trimble has the extra precision in their GGA messages too.