Personally I see the use of facing as more realistic but significantly less fun if universally applied. Let’s be honest: in a zombie-strewn apocalyptic wasteland with danger around every corner, I’m sure that it goes without saying people would be constantly checking in every direction.
I was pretty unimpressed by the rather fussy nature of unreal world which included facing as an issue.
The most/only acceptable versions IMHO would be to along the lines of:
-a narrow blindspot cone behind the player, perhaps with a new zombie type (burrowing? silent? enhanced tracking?) that could exploit this and generate some more tension - or one that was triggered by particular conditions such as intoxication, or
-if it were tied into the implementation of running: I think that a reduced cone of vision might help to counter balance the advantages of additional speed and the possibility of a fast zombie catching up with you in this blindspot might add some tension to an otherwise risk-free escape.
Personally speaking, gameplay-wise a much larger visible screen area is surely a much higher priority (although the reality is that bringing tiles support up to date would undoubtedly bring the most new players in). The current window is unnecessarily restrictive - spending ime hitting “x” and manually panning is a nuisance so a larger screen would reduce the inconvenience and speed of play rather than add any inherent player advantage. It might also be an opportunity of rebalancing sight +ve and -ve traits and the otherwise no-brainer use of binoculars.
I do appreciate the hard work of those actively involved in the project / and regret I have no coding skills to help. I do appreciate that suggestions such as a larger screen area and/ or tiles are non-trivial tasks!