Yes, for the calculatyed & certified distance TRs are not considered.
But they are effective, nevertheless, and the question was asking which was more effective, not which were considered.
I don't know about other manufacturers, but the loss of braking mu is considered directly in calculating the distances on wet and contaminated surfaces for our manuals, and I believe that's what the regs require. Certainly it's rather more than a crude weight reduction.
(weight would only be reduced if one held the LFL or ALD constant, otherwise the distances just go up as the decel devices become less effective)