This leads to an interesting debate whether an ADF should be used for flying these; suprisingly there appears to be no legal requirements for that
It's by default, unless you have a legal approach-approved IFR GPS installation and operational approval to fly "overlay" GPS procedures.
I think the point of DME and ADF being required to be carried but not required to be used is that there can be approved alternatives for
use in an FMS-equipped aircraft (but requiring the radio kit to be carried as a back up or cross-check)