VLC is a great way to work with AppleTV, if you are willing to trade a few more clicks and less meta data for being free. It is by far the gold standard of being able to play anything.
The file format issue, plus the simple interface (especially for older less technically inclined) makes infuse worth the $100 lifetime cost (especially with family sharing).
What hardware are you using for your LibreELEC? Pi 3,4,5? With an external drive?