Windows 11 (24H2/25H2): real-world multi-client MIDI support in DAWs?

[enCiphered]

With Windows 11 24H2 / upcoming 25H2 Microsoft has introduced the new Windows MIDI Services stack (supporting MIDI 1.0 + MIDI 2.0, shared endpoints, app-to-app routing, etc.).

One of the key architectural changes is supposed to be true multi-client MIDI, i.e. a single physical MIDI device can be opened by multiple applications simultaneously at the OS level, without virtual drivers or exclusive locks.

On paper this finally removes the long-standing WinMM limitation, but I’m curious about real-world behaviour in actual DAWs and hosts:

- Can the same hardware controller be used in parallel across multiple DAWs?
- Do DAWs still open devices in exclusive mode despite the new stack?
- Any confirmed cases where different mappings per DAW work simultaneously?
- Any caveats with feedback, MIDI out, or legacy APIs?
- other limitations, undocumented behaviour, or DAW-specific quirks worth discussing?

I’m aware this is an ongoing rollout and that DAW support will likely lag behind the OS changes, so I would love to see some real-world tests and edge cases at this stage.