  We investigate the effects of saturation dynamics on midrapidity flow
observables by adding fluctuating hotspots into the novel Monte Carlo EKRT
(MC-EKRT) event generator for high-energy nuclear collisions. We demonstrate
that the intensity of the saturation effects significantly affects the ratio
between the flow coefficients $v_3$ and $v_2$ at the LHC. Adding a hotspot
substructure to the nucleons enhances the saturation effects and improves the
agreement with the measured data. We show that the collision-energy dependence
of the flow coefficients obtained using the MC-EKRT initial states with
hotspots is improved in comparison with the earlier event-by-event EKRT model.
In addition, we present the results for the charged hadron multiplicity
distribution in Pb+Pb collisions at the LHC, and show that the
minijet-multiplicity originating fluctuations of the saturation scale included
in MC-EKRT, as well as the presence of hotspots, are necessary for describing
the measured large-multiplicity tail in the distribution.
