I recently purchased a Minix T5 for the purpose of running CoreElec.
Hoping my experience might help others.
The firmware was a build behind,so I updated that first.
I placed the downloaded Minix zip on a sd card and held the reset button down with a paper clip while powering up.
The update went thru once I selected the file offered up on the bottom of the screen.
I then flashed an SD card with CoreElec and did the Device Tree thing.
Everything runs well,but I did notice a quirk in the Netflix app.
Some 1080 movies would play without an issue,but one or two had frame skipping and the video and voice got out of step.
The fix was to enable VP9 in the Netflix app Expert settings.
On my Pi3 B+ and old Minix U1 I had artefacts after selecting VP9,but not with the T5.
Everything works really well.
Loving Minix and CoreElec.
Many thanks to everyone involved with the project.