On the robustness of triaxial Schwarzschild modelling: The effects of
  correcting the orbit mirroring
  In the past 15 years, the triaxial Schwarzschild orbit-superposition code by
van den Bosch et al. (2008) has been widely applied to study the dynamics of
galaxies. Recently, Quenneville et al. (2022) reported a bug in the orbit
calculation of this code, specifically in the mirroring procedure that is used
to speed up the computation. We have fixed the incorrect mirroring in DYNAMITE,
which is the publicly-released successor of the triaxial Schwarzschild code by
van den Bosch et al. (2008). In this study, we provide a thorough
quantification of how this bug has affected the results of dynamical analyses
performed with this code. We compare results obtained with the original and
corrected versions of DYNAMITE, and discuss the differences in the phase-space
distribution of a single orbit and in the global stellar orbit distribution, in
the mass estimate of the central black hole in the highly triaxial galaxy PGC
46832, and in the measurement of intrinsic shape and enclosed mass for more
than 50 galaxies. Focusing on the typical scientific applications of a
Schwarzschild triaxial code, in all our tests we find that differences are
negligible with respect to the statistical and systematic uncertainties. We
conclude that previous results with the van den Bosch et al. (2008) triaxial
Schwarzschild code are not significantly affected by the incorrect mirroring.
