Of course it may not do anything, depending on how the DSLAM is configured.
Or there's also the possibility that it might not be something restrictive on the DSLAM but instead could be that
--tones only works on ADSLx connections (much like the BDCM's SNRM tweak). I'm pretty sure I tried this once and it did nothing on FTTC/VDSL2, unlike the Mediatek chipset which did.