Ok- D series baitrunners are light tackle reels not designed for locking up drags- having said that if you manage to melt the drag catching the average bonito/rat king/school jew that you are likely to catch of the shore in the harbour then congrats. i havent melted a drag on a reel EVER in 35 plus years of catching big, fast fish. Had plenty of reels with crook drags that faded when they heat up or got wet but 95% OF modern reels simply dont have that problem.Any issues that i am aware of from the D series were from guys fishing totally innappropriate line and drag settings on those reels (65Lb braid for example). Dont be fooled by the idea of "drag power"- most guys i know cant pull 6 kg of drag for more than 10 minutes without a harness (including a mate of mine who is an ex NRL player)- all that you are going to achieve by locking your drag when fishing the stones is breaking gear, putting yourself in a dangerous position and possibly getting hurt. Learn how to play a fish, get a set of scales and set 5kgs of drag on a reel and see how damn hard it is to pull.