Could try this...
I haven't experimented with spawnmaster, but you could try this:
Add a variable to your macro
AlertMobIsUp boolean (T/F)
Then add the lines:
/if (!${AlertMobIsUp} && $(SpawnCount[MOB I WANT TO KILL's name]}>0) /multiline ; /varset AlertMobIsUp TRUE ; /beep 1 ; beep 1 ; beep 1
/if (${AlertMobIsUp} && ${SpawnCount[MOB I WANT TO KILL's name]}<1) /varset AlertMobIsUp FALSE
Keep in mind, some named have shown up in 2 spawn points at the same time. It's crazy rare, but I've seen it happen.
Pro and Con of both methods:
DLLs are usually cleaner and don't require running perticular macros.
DLLs can break or not be updated when new releases are put out. If the most basic MQ2 works, macro checks should work.