I play FLAC via Rockbox with a 5th gen iPod Video and it’s able to keep up. I did find that if the music files have the album art embedded in them (especially high resolution art) that it SERIOUSLY bogs down the iPod as it tries to downsize the photo. Once I fixed that, it plays FLAC just as promptly as any mp3.

I have the Ultimate Bluetooth Controller from them and it’s been plug & play on everything I’ve tried. Fedora with KDE picks it up on 2.4GHz mode just fine (and Steam recognizes it too). My iOS devices recognize it as a Nintendo Switch Pro controller when using Bluetooth mode.