  We conduct hydrodynamical MOND simulations of isolated disc galaxies over the
stellar mass range $M_{\star}/M_\odot = 10^7 - 10^{11}$ using the adaptive mesh
refinement code \textsc{phantom of ramses} (\textsc{por}), an adaptation of the
\textsc{ramses} code with a Milgromian gravity solver. The scale lengths and
gas fractions are based on observed galaxies, and the simulations are run for
5~Gyr. The main aim is to see whether existing sub-grid physics prescriptions
for star formation and stellar feedback reproduce the observed main sequence
and reasonably match the Kennicutt-Schmidt relation that captures how the local
and global star formation rates relate to other properties. Star formation in
the models starts soon after initialisation and continues as the models evolve.
The initialized galaxies indeed evolve to a state which is on the observed main
sequence, and reasonably matches the Kennicutt-Schmidt relation. The available
formulation of sub-grid physics is therefore adequate and leads to galaxies
that largely behave like observed galaxies, grow in radius, and have flat
rotation curves $-$ provided we use Milgromian gravitation. Furthermore, the
strength of the bars tends to be inversely correlated with the stellar mass of
the galaxy, whereas the bar length strongly correlates with the stellar mass.
Irrespective of the mass, the bar pattern speed stays constant with time,
indicating that dynamical friction does not affect the bar dynamics. The models
demonstrate Renzo's rule and form structures at large radii, much as in real
galaxies. In this framework, baryonic physics is thus sufficiently understood
to not pose major uncertainties in our modelling of global galaxy properties.
