After researching I confirm that I was able to flash the MK firmware like this:
- download modified Asus flasher (out of this post)
- download the MK firmware https://www.makemkv.com/forum/viewtopic ... 19&t=19113
Select the MK firmware in the Asus flasher, done! Reading UHD disk as I write this post
![Wink ;)](./images/smilies/icon_wink.gif)
The SDFtool flasher produced an error 0x8f05c103 and did not do the job.
And last but not least... I didn't read everything close enough which made me brick my old drive. It is a BH16NS40 manufactured June 2014. If anyone has tips how to get it to work again... but I needed a new drive anyway as the old one, to my understanding now, will never read UHDs. Just a shame that now I have to throw it away...