It's not as if they can build more at LHR and PIK is close to both DUB and LHR/LGW. "Why send your A380s to Manila for heavy checks via Clark
IAG like Lufthansa Technic has offshored mainly because it makes no financial sense in a globalised economy to keep that level of cost at first world levels. I am sure that BAMC in Cardiff would not be built today. The cost difference is so big, even sending an empty A380 to overnight at LGW for another crew to fly to MNL or Clark still looks like nothing against the cost saving of using the offshore maintenance.
As for AGS, they’re struggling to focus on making the existing group portfolio make any sense, adding in PIK won’t help that.