I've not used TACC significantly, instead sticking with Autosteer and NoA on divided highways. But since recent update, have been testing quite a bit with TACC. So TACC and 'local roads' a bit alien to me.
May be related, but whilst I was on TACC I did notice it slow nicely for a parked car until I started steering to go around it when it then nicely resumed normal speed again.