  Context: The pre-main sequence evolution is often simplified by choosing
classical initial models. These have large initial radii and sufficient uniform
contraction to make them fully convective. Contrary to that, real stars are
born as small protostellar seeds in collapsing molecular clouds and obtain
their final mass by means of accretion. Aims: We aim to constrain the input
physics of accretion on protostellar seeds with observed spectroscopic
parameters and stellar pulsations of young stellar objects and pre-main
sequence stars. Methods: We conducted a literature search for spectroscopic
samples of young stellar objects and pre-main sequence stars including all
previously known pulsators. The sample size of pulsating pre-main sequence
stars is increased by analysing TESS observations and presenting discoveries in
CoRoT data. We employ MESA and GYRE to calculate evolutionary tracks of
accreting protostellar seeds in a constant accretion scenario, the subsequent
pre-main sequence evolution, and their pulsation properties. The results are
then compared with observations to constrain the input physics. Results: We
discuss 16 formerly unknown pulsating pre-main sequence stars and candidates
that are either of SPB, $\delta$ Scuti,$\gamma$ Doradus or $\delta$ Scuti -
$\gamma$ Doradus hybrid type. We find that evolutionary tracks with a mass
accretion rate of $5\times10^{-6} M_\odot/{\rm yr}$ and fraction of injected
accretion energy of $\beta=0.1$ provide the best results in enveloping the
spectroscopic parameters of pre-main sequence stars in a constant accretion
scenario. The calculated instability regions constrain the atmospheric boundary
conditions to Eddington Gray atmospheres; we discuss the future potential for
additional constraints by instability regions that are dependent on radial
order. We present a possible candidate for pulsations in M-type young stellar
objects.
