Yes, but obviously ensure you notionally stay the weekend, and use the Multi City option. Now this is a variation of Hidden City, but it is so obscure that it must be a huge way down BA's hit list, but it surprisingly does work. To stay the right side of this, you can of course make the notional return to AMS (or where-ever) actually worth taking by adding a long back date. Add BCN, ALC and VLC to that list too (and presumably JER, but I've not checked that).

It's the yellow box wrap to PMO in ET, pictures in the food photo thread, so effectively 2 sarnies, crackers, lump of cheese and mini pud.

You are unlikely to get a POUG on PMO since the service is new and POUGs are not offered on brand new routes. You would have been more likely to get one from CAT however, since that is well established. I bet PMO won't be offering full ticketing, so I doubt AUP would be available. Theoretically you're looking at £120 a head on this or thereabout, and since it's one of the longest 40 TPs routes it's not particularly good value.

The low cost Euro price from PMO is no surprise at all, I managed to book a flight on PMO to LHR at a stonking 47.41€! That's in O so not open to UuA, so the trick is to overpay into the N bucket, for an extra 36€ or so. This may not work, redemption availability may not come around, but on a new route I think 2 seats would at some point, both for UuA and for straight redemptions.

If you have already booked this, you have potentially the option to upgrade to N bucket for the change fee (80€ I guess), the fare difference (36€) and then UuA Avios and fees - so not much change from 140€ or so. But best to book into N in the first place in this scenario.