We have had this patch available since late 2019, through software you can get rid of around 90% of the noise but will still be present very slightly. I don't see it being possible to get rid of this noise 100% as the waste gate still needs to open at some point.
Only solutions I have seen to get rid of this completely so far are by fitting a big turbo kit or a TTE777 hybrid turbocharger as they port the waste gate arm, combined with a waste gate rattle patch it eliminates 100% of the rattle.
Something some of my other customers have been doing is fitting RS3 8v pre fl Secondary catalyst pipes. This works well, gets rid of the Decat fumes but kills a little noise.
I'm thinking of speaking to MRC to fix the wastegate rattle (or partially, it seems) and uprate the brakes at the same time. I may even ask them to dyno it as the last dyno was on one of the very hot days and power was down.