IME, GAs are best at accommodating a single request. When I ask for an aisle seat, bulkhead, or exit row (asking for extra legroom, as I am 6'5"), the GA is usually able to offer me a decent seat assignment. If you have a tight connection, I would explain that to the GA and ask for a seat in the front of Y. If you need legroom/lavatory access, I would explain that.

It seems to me that GAs are more than willing to accommodate legitimate requests, but are immune to the usual DYKWIA requests for EC/aisle seats. If you approach the GA and can offer even the most flimsy of rationale for the seat you want, you will likely get it. If you badger the GA or repeatedly ask about seats, you will probably find yourself in a middle seat toward the back of the plane.

Maybe this isn't fair, but there are plently of reasons people need to ask for special seating, and being a DYKWIA seems to be the default assumption if a better reason isn't offered first.