No tune yet.
All turbo cars have some lag and it's just the nature of them. It is barely noticeable on my 335 and now f10.
Maybe you have too high of an expectation for the 535? Turbos just won't ever feel like a NA car if that's what you are after. Even the mighty M5 has some lag according to reviews.
Mineral White/Mugello 2016 F85 X5M