Agreed, lots of people leave their large checked bags behind the counter (I think there's a closet) while they shower and have breakfast. So unless the poster is tight on time for the onward flight baggage cutoff, this would be more efficient then going upstairs and back down (and then back up).

Separate note, the food offering on the buffet is pretty decent (lots of smoothies, fruit, pastries, yogurt/muesli), but do avail yourself of the made-to-order items from the kitchen as well -- full English, usually something with smoked salmon, sometimes avocado toast. You'll have to proactively flag down one of the servers to order, but this is what elevates the lounge from decent to very nice and many people don't realize.