Let us openly acknowledge that the PILOT must be able to freely choose his landing speed. Let us also acknowledge that ATC is merely trying to make things work and stuff 5 pounds of sugar into a 3 pound sack.
so, dear ATC, I would think that you should hear the word "UNABLE" more and more often and YOU should prepare for that.
during the famed berlin airlift, when the C54 was the primary plane, all the speeds were the same and you could run it like a railroad.
but now, there are a wide variety of planes and speeds.
and if ATC gives a clearance, 160knots to 4 dme, AND DOESN"T ALLOW TIME TO LISTEN for a reply, you must assume you might not get what you asked for.
I say, ATC change YOUR procedures...any speed from the FAF inbound is ok, speed adjustments only allowed prior to the FAF/OM/GS intercept.