  Electronic structure enhancement factors of simultaneous parity and
time-reversal violation ($\mathcal{P,T}$-violation) caused by an electric
dipole moment of the electron (eEDM) and scalar-pseudoscalar nucleon-electron
current (SPNEC) interactions are reported for various metal mono-hydroxides,
several of which are considered laser--coolable and promising candidates for an
eEDM measurement. Electronic structure enhancements are calculated \textit{ab
initio} within zeroth order regular approximation (ZORA) for CaOH, SrOH, BaOH,
RaOH and YbOH. Scaling behavior with respect to nuclear charge numbers and the
ratio of enhancement factors for both discussed sources of
$\mathcal{P,T}$-violation are analyzed, which are crucial to obtain stringent
bounds on parameters for new physics from experiments.
