User blog comment:SlyCooperFan1/Ace Combat Infinity Update 13/@comment-25370154-20160122235258/@comment-179.183.144.234-20160126210814

the Firepower Enhancement Plan L and the Homing Enhancement Plan L are the L versions of the Plans for Improved Destructive Capabilities and the Plans for Improved Homing Capabilities with different names

and the effects do stack up so you will get more homing or damage if you stack combined and normal parts