Most stars in our galaxy form in systems, whose architecture and composition are fossil records of
their formation and evolution. Particularly for brown dwarfs and exoplanets, belonging to a system is
a key advantage for their characterization and the calibration of evolutionary and atmospheric
models. In this talk, I will provide a status update on the multiplicity statistics within the 20pc
census, and lay out multiple ongoing efforts to characterize benchmark systems and confirm
candidate ones with Gaia-Hipparcos accelerations, double-PSF fitting, and spectral binary fitting
prior to the upcoming Gaia DR4. These benchmark systems are also our best atmospheric
laboratories to disentangle confounding parameters and their effect on spectroscopy. Together, these
studies bridge separate populations that look alike in their fundamental and atmospheric properties
but differ in origin, leveraging that contrast to trace their stellar or planetary formation histories.