LOL- my complaints fell on deaf ears for months at the ARB supplier I purchased from. They really had me second guessing my install abilities. It wasn't until I heard chatter on the Australian forums that I started going over the suppliers head trying to contact ARB. I have yet to hear a supplier comment about clunking.
I've sold, installed and driven dozens of BP-51 setups and I've commented a great deal here on the forum and with customers. Cold fluid through bypass valves... makes clunks and I too hope they can find a long-term fix through valve changes and viscosity mods. We have ~$12k worth of Kings on the Canguro 200. The bypass shocks are noisy as hell until they warm up.