Cross-posting for consistency:
We generally try to be thoughtful about which features we add to our Device OS because more features means more flash and RAM used by the system and less resources available to your application. Since the primary role of Bluetooth in Particle Mesh is for device setup and diagnostics, we don’t plan to support generalized and broad Bluetooth functionality when we ship.
Can you share a specific use case for HID or other bluetooth profiles? FWIW, we're considering using Nordic's BLE uart for the low-level device setup and diagnostic primitive.