Config setting for Backrooms to determine roundstart spawn or not

code/controllers/configuration/entries/general.dm

@@ -555,3 +555,8 @@
 /datum/config_entry/flag/demos_enabled
 
 /datum/config_entry/flag/toast_notification_on_init
+
+/// Whether the backrooms will spawn at roundstart or not. This is a very intensive process that can tack an extra 30+ seconds to roundstart
+/// and creates an extra z-level full of mobs that will add extra load to the server. Only enable this if you're sure you want it. Or optimize it for me.
+/datum/config_entry/flag/backrooms_enabled
+	default = FALSE

code/controllers/subsystem/backrooms.dm

@@ -1,7 +1,9 @@
 SUBSYSTEM_DEF(backrooms)
-	name = "Procedural Generation"
+	name = "Backrooms Procedural Generation"
 	init_order = INIT_ORDER_BACKROOMS
-	flags = SS_NO_FIRE
+	flags = SS_TICKER | SS_BACKGROUND | SS_NO_FIRE
+
+	var/noNeed = FALSE
 
 	var/datum/map_generator/dungeon_generator/backrooms_generator
 	var/datum/generator_theme/picked_theme = /datum/generator_theme
@@ -16,16 +18,19 @@ SUBSYSTEM_DEF(backrooms)
 		/obj/item/toy/plush/lizard/azeel = 5000
 	)
 
-/datum/controller/subsystem/backrooms/Initialize(timeofday)
-	var/noNeed = FALSE
+/datum/controller/subsystem/backrooms/PreInit()
 #ifdef LOWMEMORYMODE
 	noNeed = TRUE
 #endif
 #ifdef UNIT_TESTS // This whole subsystem just introduces a lot of odd confounding variables into unit test situations, so let's just not bother with doing an initialize here.
 	noNeed = TRUE
 #endif
 
-	if(noNeed) //we do it this way so things can pass linter while in low memory mode or unit tests
+/datum/controller/subsystem/backrooms/Initialize(timeofday)
+	if(!CONFIG_GET(flag/backrooms_enabled))
+		noNeed = TRUE
+
+	if(noNeed)
 		return SS_INIT_NO_NEED
 
 	pick_theme()
@@ -34,6 +39,15 @@ SUBSYSTEM_DEF(backrooms)
 	spawn_loot()
 	return SS_INIT_SUCCESS
 
+/datum/controller/subsystem/backrooms/stat_entry(msg)
+	if(noNeed || !CONFIG_GET(flag/backrooms_enabled))
+		msg = "DISABLED"
+	else if(!noNeed && !initialized)
+		msg = "Generating..."
+	else
+		msg = "Theme: [picked_theme]"
+	return ..()
+
 /datum/controller/subsystem/backrooms/proc/pick_theme()
 	var/list/themes = typesof(/datum/generator_theme)
 	for(var/datum/generator_theme/possible as anything in themes) //assign the weight

config/config.txt

@@ -463,3 +463,6 @@ MAX_SHUTTLE_SIZE 300
 ## Comment to disable sending a toast notification on the host server when initializations complete.
 ## Even if this is enabled, a notification will only be sent if there are no clients connected.
 TOAST_NOTIFICATION_ON_INIT
+
+## Enable/Disable Backrooms z-level generation at startup
+BACKROOMS_ENABLED