Probably the worst idea regarding a Backrooms map
The whole point of The Backrooms is an endless series of halls, everything looks the exact same and the entire concept kinda personified internet horror in the early 2020's (The monsters kinda ruin it tho) As a map for Dead By Daylight, it would effectively house another piece of horror in this beautiful horror museum.
And as for my horrendous idea: the map would be entirely randomly generated. Something that I don't think I have to explain why I consider that a terrible idea, however sense I'm crazy enough to entertain this, it would be a square base with map elements randomly placed, making it so you don't know where to find generators and the killer is struggling to find you because he's also suffering from the map geometry. If the randomly generated route is too substantial, there could instead be several preset layouts like The Nightmare on Elm street map (before the other variants were retired) only the backroom layouts wouldn't be labeled, to really sell the idea that no trial in the backrooms are the same.
Chapters solely existing to add maps kinda sound like a bad idea, but there is a backrooms film coming out, so maybe we could get a Survivor to justify this weird map concept.