Scratchen

Well I've been testing today again, taking around 3000 shots at CH 11fps. Uncompressed RAW. No lockups!
 
Just tried switching it back to compressed RAW, and guess what, it locked up within the second burst of shots, took just a few seconds. Again, I had to remove the battery grip to reset it.
 
To be sure, I did this twice, and it locked up both times.
 
So for me it's a no brainer, the compressed raw is to blame.

Just wanted to share my observations. I've owned the X-T2 since september 2016, and I've pretty much been having lockups since day one - always in CH or CL. The lockups would freeze the camera completely, sometimes with a white EVF/LCD, and the green/orange LED being constantly orange. The only way to get it out of the lockup would be to remove the batteries in the grip.
At first I was using third party batteries in the booster grip (but the original NP-W126S in camera). Then I read it might be a battery related problem, so I bought two more NP-W126S. Didn't fix anything...
Then I read it might be related to my Lexar 64GB 150MB/s UHS-II cards, so I bought two new Sandisk 64GB 300MB/s UHS-II cards. Didn't fix anything either...!
At this point it started to get pretty expensive...
Scanned through every thinkable menu option and tried switching off "compressed raw". Well, I've been pushing my X-T2 all day now, shooting about 300GB of photos at 11fps, WITHOUT any freezing!
This could be it. I'll continue to test this, and get back to you.