I have a 2018 in .177 that apparently has a TBT kit in it. Cocks and shoots very nicely. I bought it secondhand and it had about 5mm of barrel droop. Once I removed the barrel and sights, it was an easy fix because my barrel doesn't seem hard. Could the droop have been caused by someone being a bit too energetic whilst cocking it?
I wouldn't let a bit of barrel droop put me off buying a gun that I otherwise wanted.