I used PCR Performance for my gen4 2020. It has a decat with Akra SS pipes and a RaceFit Growler end can. Andy, in their Dyno room, is an absolute star. Having re-mapped her, with some regularity when you pulled the clutch in for downshifting at low speeds the engine just cut out - quite scary at times, as you had to restart her with the starter button (only split-seconds, but depending on traffic conditions...). Anyway, Andy had her back in on two occasions and spent quite some hours getting to the bottom of it (all at no extra cost). He was in regular contact with the Italian company who make the ECU and eventually found the answer in a particular 'switch' to turn on. On the half hour journey home all was good, but need to take her out for a good blast to properly test her.
PCR are a great outfit and I highly recommend them. Andy did explain that with most jap bikes they can just re-use one of their maps 'off the shelf', but with BMW's they are all different and need proper tuning from the get-go.