Short check offered at JFK

It could be chance, but on the return leg of my last three BA/VS/VS/BA ex-EUs (JFK-LHR-CPH x2; JFK-LHR-AMS x1), the VS check-in agent at JFK has offered to short check my bag each time. These are VS-UC-to-BA-CE leg with a T3-T5 transfer at LHR.
The discussion comes up because I travel with hand luggage only, and the agent will almost always ask if I want to check-in any of these bags. I always say that I have a long layover at LHR, and that I might need access to the contents of the bags, so I'd prefer to keep them on me. That's when the short check offer is made by the agent.
I don't want to start yet another discussion about the pros and cons of not taking the final sector (I never do, but I understand entirely why people do). I always book a layover of four or more hours at LHR.
The discussion comes up because I travel with hand luggage only, and the agent will almost always ask if I want to check-in any of these bags. I always say that I have a long layover at LHR, and that I might need access to the contents of the bags, so I'd prefer to keep them on me. That's when the short check offer is made by the agent.
I don't want to start yet another discussion about the pros and cons of not taking the final sector (I never do, but I understand entirely why people do). I always book a layover of four or more hours at LHR.