Whenever there is doubt about the point estimates of the equilibrium funds rate, the inflation target, or the unemployment target, the Taylor Rule can be converted to a change rule.
If levels of inflation and unemployment seem to be at least within their target bands, if not at unknown point estimates of the target, monetary policy can just try to keep inflation and unemployment in these desirable bands. Policy would respond only when movements in the economy threaten to take inflation and/or unemployment out of their preferred bands.