Just got it, tested fits perfectly for my Mini 4, do not have to remove it to close/shutdown the controller if you don't use lanyard block (which I never use lanyards) nice feature for me, Easy swap from Android phone to IOS Mini.
Yes indeed, it took 4 days but I got it yesterday and used it on my Nvidia K1. The strap block is nice too, it adds security to the phone. I'm not sure how long the block will last since you have to take it off to close the controller.