I bet it made no difference to your ADSLx connection, and wouldn't do so on VDSL2 either.
I got one with an ADSL Nation XTE-2005. Sync's through the faceplate were consistently a couple of hundred kbps lower than with most of half-a-dozen danglies, and the cable was exactly the same performance as all of the ones I have from various routers.
Noise margin behaviour monitored with RouterStats or DMT was unchanged with either or both of the ADSL Nation bits. Which are in their delivery packaging in a drawer.
My broadband basic info/help site - www.robertos.me.uk
My domains,website and mail hosting - Tsohost.
Internet connection - IDNet Home Starter Fibre.
Live BQM.
"Where talent is a dwarf, self-esteem is a giant." - Jean-Antoine Petit-Senn.