3x daily SNN-LHR
I wonder is the extra slot coming from Dublin, Cork or Belfast.
Cork probably wouldn't make sense in terms of aircraft utilisation, but what this could mean for Belfast is interesting to say the least.
As regards the A321 to ORD.
I don't think it's possible without modification to fit extra fuel tanks. Also, flying A32x series transatlantic is prohibitively expensive and only worthwhile if you have a lot of business passengers.