All I want is to send gapless FLAC to my dac
Are you sure? If YES, then how does it matter that it is sent via a computer Vs a transport? How are you sending these FLAC files to the DAC, if not using a computer?
My Panasonic 9000 says it does gapless playback, but also notes that some differences in the files that are supposed to be continuous may cause issues. I have never tried the gapless playback but now have a reason to :-) Using a dedicated device other than your regular computer to play files is always better. I find all kinds of artifacts that show up audibly when my computers are feeding the content to my DACs. Mostly gaps where something happens in the computer that must have a much higher priority that it affects the file output. Not probably a big deal for kids listening to MP3 files on a cheap powered speaker, but a deal-breaker for using computers with a high end system and critical listening.
During the pandemic I got JRiver and played with all types "renderers". DVD players, Blueray players, Sonos speakers TVs etc. With JRiver I can see a variety of details at the renderer level which is key. A very large amount of my music is gapless.
My results are simply that the regular DVD/Blueray players are quite unreliable in this regard with none being solid. I even did the same with a relatively new Sansung TV and while no gapless but it also resampled everything to 16 bit no matter. One TV actually reversed the channels when uses as a renderer.
So despite what should be a super simple job to achieve I purchased a real audio streamer which of course does gapless and other things they way they should be done for an audio user.
You only gain something from gapless playback if two or more tracks are intended to play with no interruption at all. A brief silence ruins this effect.
If I use a computer as transport, the only way I can connect to my dac is with USB. My blue-ray player allows for a spdif, hdmi, or toslink connection cable.
The player gets the files either from an optical disk that I insert (CD-R or DVD-R) or a USB drive or flash drive. A Red Book CD can also be used in the disk drive. Of course, the gapless issue does not depend on this. My player just doesn't do gapless, but others are gapless (which is the point of my original message).
Since my Sony Blu-ray player does everything OK except for gapless and the real gapless players seem to cost around 10 times more than the Sony, I just leaving things as they are for now. Gapless tracks are a small percentage of what I listen to and in the worst, case, I can easily create a single file with no gaps.