To answer your earlier question about whether the ground stations can tell the difference between certified and non-certified position sources, yes, the ground stations see the SDA parameter in your squitter and know if you are 2020 compliant with an SDA of 2 or if you are non-compliant with something less.
Today, ground stations do not deny any services (including TIS-B uplinks of Mode C traffic and ADS-R rebroadcast of ADS-B traffic) just because your position source is non-certified.
Just a reminder that FIS-B weather is broadcast to everyone, so this also has nothing to do with the design assurance of your position source.