Yeah, we made both of those assumptions. But it's apparently less true of the latest generation of compute engines. We probably won't bother with CUDA, but Metal is certainly a viable platform to try. It's one of those things where nobody really knows how it'll do until you try it.

Also, we do know a few people who want to use SOUL to write audio code which does need high parallelism. It's not a super-common use-case for audio, but it does exist.