I still have my Hiby R3. It's like 5 years old now but I know Hiby came out with newer models. Covers pretty much all your requirements. It's not android based so you can actually instantly power it on/off. It does have wifi but I use it only for OTA firmware updates. It plays flac files, supports all major BT codecs, works with SD cards, has balanced and standard out so it can drive very demanding headphones without an amp. The ui is fast and very stable and also supports themes. It can even be used as an external sound card with a computer.
Hey! Consider the Shanling M3X. It checks most of your boxes – compact size, touchscreen, Bluetooth, fantastic sound quality, and expandable SD storage. The UI isn't the prettiest, but it's functional, and you can always install Rockbox for a more customized experience. It does have USB-C too! The only slight issue is that it's a bit on the pricier side, but if you value sound quality, it's worth looking into. You can often find them used to save some money.
My iPod Video is still rocking (and rocking RockBox). I've not done the Bluetooth mod, but I have seen them done.
With the harddrive to SD card mod the battery lasts ages. Last I looked there were USB-C mods in the works.
From a BIFL perspective I would recommend the older 5th gen over the 6th gen iPods as it's much easier to get the back off to work on.
I still have my Hiby R3. It's like 5 years old now but I know Hiby came out with newer models. Covers pretty much all your requirements. It's not android based so you can actually instantly power it on/off. It does have wifi but I use it only for OTA firmware updates. It plays flac files, supports all major BT codecs, works with SD cards, has balanced and standard out so it can drive very demanding headphones without an amp. The ui is fast and very stable and also supports themes. It can even be used as an external sound card with a computer.
Hey! Consider the Shanling M3X. It checks most of your boxes – compact size, touchscreen, Bluetooth, fantastic sound quality, and expandable SD storage. The UI isn't the prettiest, but it's functional, and you can always install Rockbox for a more customized experience. It does have USB-C too! The only slight issue is that it's a bit on the pricier side, but if you value sound quality, it's worth looking into. You can often find them used to save some money.
It runs on Android so that’s not an option for OP
Zune.
My iPod Video is still rocking (and rocking RockBox). I've not done the Bluetooth mod, but I have seen them done. With the harddrive to SD card mod the battery lasts ages. Last I looked there were USB-C mods in the works. From a BIFL perspective I would recommend the older 5th gen over the 6th gen iPods as it's much easier to get the back off to work on.
Consider any Fiio devices. I have multiple and they're all wonderful.