A3:F4E0 - New Metroid Initialization AI. Will JMP to old initialization if spawn succeeds, else, STZ to enemy and RTS.

	JSL $808111
	AND #$00FF
	LDX $0E54
	CMP $0FB4,X
	BPL Spawn
NotSpawn:
	STZ $0F78,X
	RTL
Spawn:
	JMP $EA4F

2211818029FF00AE540EDDB40F10049E780F6B4C4FEA


And of course, change the Metroid entry to point to this new startup:

A0:DD91
E0F4

... seems to work just fine. Wow. First try and all.