Open turfs handle space below

code/game/turfs/turf_changing.dm

@@ -24,7 +24,7 @@
 	// This makes sure that turfs are not changed to space when one side is part of a zone
 	if(N == /turf/space)
 		var/turf/below = GetBelow(src)
-		if(istype(below) && !istype(below,/turf/space))
+		if(istype(below))
 			N = /turf/simulated/open
 
 	var/old_air = air

code/modules/multiz/turf.dm

@@ -106,3 +106,21 @@
 //Most things use is_plating to test if there is a cover tile on top (like regular floors)
 /turf/simulated/open/is_plating()
 	return 1
+
+// This is for handling light on open turfs above space turfs
+/turf/simulated/open/update_mimic()
+	. = ..()
+	if(!.)
+		return
+	var/turf/T = GetBelow(src)
+	if(!istype(T))
+		return
+
+	if(T.dynamic_lighting)
+		dynamic_lighting = TRUE
+		shadower?.color = initial(shadower.color)
+		lighting_build_overlay()
+	else
+		dynamic_lighting = FALSE
+		shadower?.color = "#00000032"
+		lighting_clear_overlay()

code/modules/multiz/zmimic/mimic_turf.dm

@@ -31,10 +31,11 @@
 
 /turf/proc/update_mimic()
 	if (!(z_flags & ZM_MIMIC_BELOW))
-		return
+		return FALSE
 
 	z_queued += 1
 	SSzcopy.queued_turfs += src
+	return TRUE
 
 /// Enables Z-mimic for a turf that didn't already have it enabled.
 /turf/proc/enable_zmimic(additional_flags = 0)