You can print forehead part in vase mode which will speed up printing a lot.
Slightly better model in:
https://www.prusaprinters.org/prints/29219-face-shield-in-33-minutes
Set this in PrusaSlicer even if you have 0.4 mm E3D v6 nozzle:
Print Settings
The rest set according to Prusa recommendations. Don't be affraid of the line in the front. If you use high temeperature it will melt together well like layers. If not, reduce acceleration in X and Y axes.
The author remixed this model.