Adding support for the Hexagon SDK in the Linux release is indeed "on the roadmap". There are a few pieces missing:
- Hexagon SDK runtime libs/apps/samples
- kernel driver to expose the IPC APIs used by the Hexagon SDK runtime
The DSP firmware that we use has support for the SDK already, but without the 2 pieces above, it can't be used.
Note that this would only enable access to HExagon through the QCOM SDK, like it is possible on Android builds. You do not get full control of the DSP. But I am assuming you were aware of that.