Is there any difference between the Stream Deck, Stream Dock and Ulanzi versions?

Functionally they are the same product. Every key type, every setting and every option is identical across all three. The differences are in the hardware and the host software.

Elgato Stream Deck. Needs Stream Deck software 6.9 or newer, Windows 10 or later, or macOS 12 or later. The dial is a Stream Deck Plus encoder action, and it uses a dedicated touch strip layout showing rotate to adjust, push to press and touch to press. Installs by double clicking a `.streamDeckPlugin` file. Gets the separate TrackThirtyTwo icon pack.

Mirabox Stream Dock, which also covers Ajazz, VSDinside and SOOMFON devices. Needs Stream Dock software 2.9 or newer, Windows 10 or later, or macOS 11 or later. The dial works but there is no touch strip feedback, because Stream Dock does not provide one. Installs from a TrackThirtyTwo Stream Dock Plugin installer. Gets the separate TrackThirtyTwo icon pack.

Ulanzi Deck D200 and D200H, running Ulanzi Studio. Windows 10 or later, or macOS 10.11 or later. The dial works on both keypad and encoder, but Ulanzi reports only the direction of a turn and not how fast, so it steps in fixed increments rather than accelerating. Installs from a TrackThirtyTwo Ulanzi Deck Plugin installer. No separate icon pack, because Ulanzi has not published a format for one. TrackThirtyTwo artwork is still on all TrackThirtyTwo keys.

Key counts are not fixed by TrackThirtyTwo. The plugin reads whatever grid your deck reports and adapts the pit limiter and spotter effects to it, so a larger deck simply gets more keys to play with.