UK based fleets don't make any commercial sense, what's the plane meant to do for the afternoon/evening?
The previous base was perfect. Eg.
The Birmingham flight left at 07:00 (perfect for the EI T/A flights which routinely land before 6am.) And was back in SNN by 10:15, leaving 1hr 35mins for BOS and 2hrs 5mins for JFK. Tight but often very doable.