@Are0h A bit of searching shows Vávra was a GamerGate supporter. There’s also this, on Czech nationalism...
https://unwinnable.com/2018/03/02/deliverance-myth-making-and-historical-accuracy/

...and this, which is a bit careful in its phrasing but makes some good points about romantic ideas of Medieval society that I associate with the far right:
https://www.rockpapershotgun.com/2018/03/05/kingdom-come-deliverance-historical-accuracy/