The whole problem is the need to collect the special philipino departure tax (not the regular deparure pax which is to be paid in cash only at the airport). Seemingly the only way the govt can collect this is to have tix issued only in the phils. But most expats/tourist are excempt, but you have to prove that you have entered recently. You have to submit your recent immigration stamp from passport.
You can issue before you arrive, but then you have to pay the extra 63 USD tax, and its a painful if not impossible task to claim that back. And of course you have the payment problem. Either troublesome wire transfer or get someone to show up for you.
Best bet is if you can have your ex-MNL flights tacked on the same e-tick numbers as your flights into MNL, as you will avoid the tax then.
I just arrived MNL today, and I pre arrival managed to have Airesources call CX to keep tix on hold for weeks, being EXP helps maybe, with a deadline on my arrival date. As I was excempt for this tax after proving entry, there were no other taxes (as the other is to be paid cash at airport), Airesources accepted me faxing my passport copies with immigrations stamps upon arrival. Thus no need to show up as noting was to be paid.
IC club staff did this for me, and even upgraded me to a junior suite with lounge access and free minibar on a PB stay
I love the Phils, but hate that the Embassy is closed (those on the guest list know what I mean)