Does not matter what you think the errors are, ATC can see what is selected on the glareshield via ADS. If you have selected 185 and you were instructed to maintain 180, they can see that. Just like they can see if you were instructed to climb to FL170 and put in FL190 on the glareshied they can see that.
Airliners transmit the data, it’s up to individual states if their ATC units use it.
NATS for example publishes speed compliance reports to operators for LHR and DXB, they know what pilots have selected.
A few scenarios where the set/bugged number is not accurate, 1 in Australia ATS can't see the set IAS, 2, I could descend in VS and disable IAS control, meaning whats in the window/bugged don't matter or 3, totally ignore the automatics and hand fly meaning all settings in the windows are just alerters and reference for the pilot. Lastly I could be flying something old that does not have IAS or Altitude settings transmitted via SSR at all, I know of a few types, esp turboprops still floating around that don't connect to said system. Also add that in some autopilot set ups I can select which input side the IAS comes from, so if the FOs side is under-reading I could select that side and get a higher speed than selecting the CPTs side.