I asked about that in December 2022:
Dual trace osciloscope - #2 by tunagenes and never saw a reply.
As @Jens.Peter.Nielsen pointed out in SD card error handling - #9 by Jens.Peter.Nielsen Electro-Smith did ‘promise’ in the original Kickstarter for Daisy:
"All firmware that we develop will be released for free under a permissive open source license(MIT). "
source
I don’t see why they think this would be an exception, and it would be useful as a hardware diagnostic. Of course it might be out in some repo somewhere and we just haven’t found it!