Valve have said they will (somehow) not count the time taken to download the game content against the 2 hour refund clock [1].
[1]: https://www.gamesindustry.biz/articles/2020-08-20-valve-assu...
[1]: https://www.gamesindustry.biz/articles/2020-08-20-valve-assu...
After 6 hours of game play (sort of - half of that been spent looking at loading screens and trying out different settings) I'm still not sure. It's oh so promising but also so insanely buggy and random.