Shuttle stuffs and gateway refactor port https://github.com/tgstation/tgstation/pull/49868/

code/modules/awaymissions/zlevel.dm

@@ -2,33 +2,34 @@
 GLOBAL_LIST_INIT(potentialRandomZlevels, generateMapList(filename = "[global.config.directory]/awaymissionconfig.txt"))
 
 /proc/createRandomZlevel()
-	if(GLOB.awaydestinations.len)	//crude, but it saves another var!
-		return
-
 	if(GLOB.potentialRandomZlevels && GLOB.potentialRandomZlevels.len)
 		to_chat(world, "<span class='boldannounce'>Loading away mission...</span>")
 		var/map = pick(GLOB.potentialRandomZlevels)
 		load_new_z_level(map, "Away Mission")
 		to_chat(world, "<span class='boldannounce'>Away mission loaded.</span>")
 
-/proc/reset_gateway_spawns(reset = FALSE)
-	for(var/obj/machinery/gateway/G in world)
-		if(reset)
-			G.randomspawns = GLOB.awaydestinations
-		else
-			G.randomspawns.Add(GLOB.awaydestinations)
-
 /obj/effect/landmark/awaystart
 	name = "away mission spawn"
 	desc = "Randomly picked away mission spawn points."
+	var/id
+	var/delay = TRUE // If the generated destination should be delayed by configured gateway delay
 
-/obj/effect/landmark/awaystart/New()
-	GLOB.awaydestinations += src
-	..()
+/obj/effect/landmark/awaystart/Initialize()
+	. = ..()
+	var/datum/gateway_destination/point/current
+	for(var/datum/gateway_destination/point/D in GLOB.gateway_destinations)
+		if(D.id == id)
+			current = D
+	if(!current)
+		current = new
+		current.id = id
+		if(delay)
+			current.wait = CONFIG_GET(number/gateway_delay)
+		GLOB.gateway_destinations += current
+	current.target_turfs += get_turf(src)
 
-/obj/effect/landmark/awaystart/Destroy()
-	GLOB.awaydestinations -= src
-	return ..()
+/obj/effect/landmark/awaystart/nodelay
+	delay = FALSE
 
 /proc/generateMapList(filename)
 	. = list()