I think I may have some information relevant to this post. K3FTW mentions not being able to find MP3 files on a 2301 Dreamcatcher in this post, and after watching downloads for the better part of three hours today, I think I know why.
I was trying to upgrade firmware on a 2301 Dreamcatcher today between 1530 and 1830 UTC. During this time period, I saw Othernet sending two MP3 files during the time period among other files: uploads/2024-06-07-Friday-voa_news.opus.mp3 from about 1530 to 1700 UTC and uploads/2024-06-08-Saturday-voa_news.opus.mp3 from about 1705 to 1830 UTC.
The following scenario occurred several times in this time frame. At 1535 UTC Othernet started transmission of uploads/2024-06-07-Friday-voa_news.opus.mp3. At 1541 UTC Othernet stopped transmission of this file in order to transmit the APRS message file that was generated at 1540 UTC. After transmission of the APRS message file completed, the uploads/2024-06-07-Friday-voa_news.opus.mp3 started again from scratch. At about 1546 UTC, the MP3 file transmission halted and the 1545 UTC APRS message file transmission began. After the APRS message file finished, the MP3 transmission began again from scratch. The MP3 transmission would be stopped over and over after completing only about 30% of the transfer. So the APRS message files are effectively preempting transmission of the MP3 (and perhaps other) files. I did see other files transmitted, Al Jazeera news files for example, but I could not tell if any of those were interrupted in order to transmit APRS message files.
So unless the Dreamcatcher 2301 board can resume interrupted transmissions, the larger files like MP3s don’t stand a chance with the preemptive interruption. This seems to be an Othernet file transmission scheduling issue, and not a board issue.