This is super cool. Using LLMs to mix together two songs that don't belong mixed together is a great usecase.
Seems though that working with those AI tools appeals to the author, that they learned and had fun, so I guess that makes it a good usecase for them specifically?
I think this tooling could be useful in the hands of more capable musicians / audio engineers / etc. as there are often repetitive tasks in DAWs and it could potentially unlock new workflows that would have been too tedious without knowing how to program.