  We present a new independent pipeline for the CMB bispectrum estimation of
primordial non-Gaussianity and release a public code for constraining
bispectrum shapes of interest based on the Planck 2018 temperature and
polarization data. The estimator combines the strengths of the conventional KSW
and Modal estimators at the cost of increased computational complexity, which
has been made manageable through intensive algorithmic and implementation
optimization. We also detail some methodological advances in numerical
integration over a tetrapyd - domain where the bispectrum is defined on - via
new quadrature rules. The pipeline has been validated both internally and
against Planck. As a proof-of-concept example, we constrain some highly
oscillatory models that were out of reach in conventional analyses using a
targeted basis with a fixed oscillation frequency, and no significant evidence
for primordial non-Gaussianity of these shapes is found. The methodology and
code developed in this work will be directly applicable to future surveys where
we expect a notable boost in sensitivity.
