You Can Now Book Aer Lingus Awards On British Airways' Website, But...

Good way of putting it, Lucky. An "enhancement," I am afraid. It's always an enhancement.

Any eastbound transatlantic flight booked through AAdvantage on BA has $700+ in taxes, the lion share being carrier imposed fees.

Wow, if these are the correct charges, this is no longer worth it. One way BOS-DUB in economy is showing a $176 surcharge. It was $37 and the return was $83.

Not sure about the $700 one, but it appears that on January 1, 2022 (or thereabouts) that Aer Lingus drastically increased their carrier surcharges (YQ) on US-DUB flights. They used to be about $70 on a roundtrip in economy, so the total taxes/fees paid by booking through the BA call "trick" was about $120. This year they shot up dramatically to $270 roundtrip (confirmed on ITASoftware Matrix), so a roundtrip now booked through the BA call center is $320 in taxes/fee. Booking through avios.com (using Aer Lingus Avios instead of BA) the total for a roundtrip is $295 in fees (which doesn't appear to have changed much in 2022). So this takes a pretty great sweet spot (26k BA Avios + $120 roundtrip from anywhere Chicago to the east, to Dublin off-peak) to a much worse deal (26k EI Avios + $295).

For Iberia DFW route, seems they’re now charging the fuel surcharge for flights leaving the US ($200 Y, $700 J) which is different from flights leaving Europe (around 120 euro). Just check ITA Matrix.
So a round trip ticket starting from US on these new routes would charge the US YQ twice.

AS is still only showing $19 in award surcharges from PHL - DUB and $53 for the other direction DUB - PHL in Aer Lingus business. Hopefully this is just a BA glitch

Booking JAL through BA.com now has about 500% higher fuel surcharges each way. So a r/t economy ticket SFO-HND is about 50k avios + $500. this was $100 a few months back (also through BA.com) So this isn’t limited to aer lingus- but I fear a trend we are going to be seeing more of.

I think this might just be domestic carriers not catching up - rather than the other way around. I hope I’m wrong.

A few days a ago, I transferred 26k miles from BA to Avios and booked a trip for mid May on EI BOS SNN RT. The all in taxes/fees were $267.
Just checked the same itinerary on BA - taxes/fees $362.87.
Could be a glitch, but I would price shop.

Every time I look at using Alaska miles on Aer Lingus to book a business class award to/from Europe, the price is 280,000 miles. It has been that way forever. You can fly economy for 30K, but business is always 280K. I have never seen a Aer Lingus business class award for less so I just laugh when it is suggested that a person can book this award. Would I have better luck using Avios?

Just booked DUB > IAD on Aer Lingus this week in business. On avios.com, it was showing 50,000 miles + $150 in taxes and fees. On ba.com, it was showing 50,000 miles + $200 in taxes and fees. I used the "combine my avios" feature to move avios from BA to AerClub and book through them, saving $50 in taxes and fees.

Note that you have always been able to book Aer Lingus business class awards online (without calling). You just have to do so through the aerclub (avios.com) website which is far less glitchy, and use "combine my avios" to move the points over, as needed.

I have used avios.com for booking IAD-DUB and DUB-IAD on Aer Lingus using Avios. The saver non-peak rate for IAD-DUB is 50K plus $141.10 (a slight increase) and 50K plus $170.07 (a slight increase). So booking at avios.com is the way to go. You can move your Avios from BA or Iberia back and forth at will.

BEWARE THE GLITCHES OF COMBINED AVIOS
Sometimes, I receive a message that my Avios cannot be combined. The easiest way to resolve this it to log out and log in again.

Second, glitch. On Combine My Avios the addresses for the accounts you are combining must be EXACTLY the same or you will get an error. This mainly show up with the auto addition of a 9-digit zip for BA that is not reflected in Avios. You need to change the BA address to the 5-digit zip. Then make the transfer before BA auto-corrects your profile address back to the 9-digit zip. You could also call or email when you have a problem, but who wants to do that? Listening to the BA music for hours on end while on hold is not advised.

The Aer Lingus 60K AS business seats still exist, they're just capacity controlled and can hard to be find. After the 60K seats are gone, they go up to 280K. Try looking at next January/ early Feb - there are still a few there

Yes, I tested, more than double tax and fee charged on economy class between DUB and YYZ.