  The juxtaposition of the precision of lepton flavour measurements and the
limited energy range of the Large Hadron Collider (LHC) to discover dynamical
degrees of freedom linked to the generation of the observed lepton mass
patterns naively suggests only a limited relevance of the LHC's high luminosity
phase. This, potentially, extends to future colliders. We show that minimal
non-standard modifications of widely considered scenarios such as the type-II
seesaw model can, however, lead to a rich phenomenological interplay of muon
precision measurements and electroweak resonance searches at present and future
colliders, with testable implications for the HL-LHC phase.
