I don't want to send emoji assets to every machine interfacing with PDA messages.

Just the chat tab.

code/game/machinery/telecomms/computers/message.dm

@@ -421,6 +421,7 @@
 							"name" = "[customsender]",
 							"job" = "[customjob]",
 							"message" = custommessage,
+							"emoji_message" = emoji_parse(custommessage)
 							"targets" = list("[customrecepient.owner] ([customrecepient.ownjob])")
 						))
 						// this will log the signal and transmit it to the target

code/game/machinery/telecomms/machines/message_server.dm

@@ -106,10 +106,11 @@
 		return "Everyone"
 	return data["targets"][1]
 
-/datum/signal/subspace/pda/proc/format_message()
+/datum/signal/subspace/pda/proc/format_message(emojify = FALSE)
+	var/message = emojify ? data["emoji_message"] : data["message"]
 	if (logged && data["photo"])
-		return "\"[data["message"]]\" (<a href='byond://?src=[REF(logged)];photo=1'>Photo</a>)"
-	return "\"[data["message"]]\""
+		return "\"[message]\" (<a href='byond://?src=[REF(logged)];photo=1'>Photo</a>)"
+	return "\"[message]\""
 
 /datum/signal/subspace/pda/broadcast()
 	if (!logged)  // Can only go through if a message server logs it