Ex-DUB J class booking. Can I dump final segment?
Best bet is to book the final segment on EI LGW-DUB (or perhaps BA LCY-DUB). That way you don't have to try to explain why you want your bags short checked.
If you book it yourself on ba.com (or other online agent like Expedia or Orbitz) then there haven't been any reports of consequences. Don't book through a travel agent though, there have been reports of consequences for agents with a high rate of this.