I would be amazed if any Cr Card company charge you a Cash Advance fee for taking your own money out of your a/c. An advance by definition would be deemed to be credit. Perhaps other financial institutions apply charges, but they can't really be called Cash Advance Fees.
Apologies if I'm incorrect on this. Best to check with Ulster Bank to be sure & get a second opinion from them, preferably a brochure that lays it all out clearly.
I've seen people pay a lot of charges on Cirrus withdrawals, so I'm pretty sure that's not the best way to go, unless UB are very different from BOI.