So I have a good update. I initially replaced the hot end and heater assembly which Bambu sent me as part of my ticket. this did not resolve the issue. Bambulab then sent me an extruder and it seems to have done the trick. I have no scraping sounds when using the hardened steel nozzle and the print comes out as nice as expected with these machines.
Thank you all for your participation and suggestions in this thread. You are the reason this community is as great as it is. Hopefully this thread will help others diagnose and rectify a similar issue.