The only reason I give people like you a pass on hating on Blade Runner is I, personally, can't stand The Matrix -- which has made me a pariah with my peer group for over 20 years now.
Interestingly enough, the screens in the film 2001 were all flat - because they were rear projection screens, with film or slides projected onto them.
Even if not keyed, the rear projection would have worked too. Doesn't matter I guess. I didn't realise 2001 had flat screens! Good pickup.