the difference would be warranty claim if there is defect (ie: GY F1 sidewall crack).
since you mentioned besides warranty, then there should be no difference in term of material/quality/performance of the same tyre same origin either it's imported through AD or PI
i think that should be some difference especially rubber compound irregardless of origin.
otherwise tyre company will just cover warranty for any tyre they made
just like we look at our car , are they same Btw AD and PI
I can said NOT 100% same, but are PI car safe to drive ? YEs because all PI car has gone through LTA homologation.
so make your own decision and remember why you made that decision
BTW I checked out the price at Sin Heak Hin @ Sin Ming Autocare #03-20
best price for Michelin PS3 225/40 18". PI selling for SGD260 made in Hungary
but the AD ones are made in Thailand and cost more. Cheapest in Singapore and JayBee
and some say Batam.