XMeters settings app crashes on Win11 - ITrayDeskBand (E_NOINTERFACE) not answered by reimplemented taskbar

[sprktune]

I've traced a reproducible incompatibility between StartAllBack and XMeters (a taskbar system-monitor app) on Windows 11, and wanted to report it with the details in case it's an easy fix on the SAB side.

Setup: Windows 11 24H2, build 26100.8737. StartAllBack 3.9.23 (5366), Win10-style taskbar. XMeters 1.0.103.

Symptom: The XMeters toolbar itself works - its DLL is hosted by Explorer, renders in the taskbar, and can be toggled via the Toolbars menu. But its settings/manager app (XMeters.exe) crashes on 100% of launches, so there's no way to configure the meters. The already-running band keeps working - only the settings app dies.

Root cause (from the crash dumps + .NET Runtime event 1026): an unhandled System.InvalidCastException thrown at XMC.App.ShowDeskBand. XMeters calls CoCreateInstance for the shell's tray DeskBand object (CLSID {E6442437-6C68-4F52-94DD-2CFED267EFB9}), which succeeds, then does QueryInterface for ITrayDeskBand (IID {6D67E846-5B9C-4DB8-9CBC-DDE12F4254F1}) - and that QI returns E_NOINTERFACE (0x80004002). In other words, the tray object provided by the reimplemented taskbar doesn't expose ITrayDeskBand, so the app throws and terminates.
I verified the interface's proxy/stub registration is intact system-wide (HKLM\...\Interface\{6D67E846...}\ProxyStubClsid32 → {C90250F3-4D7D-4991-9B69-A5C5BC1C2AE6}), and the CLSID carries only an AppID (runtime factory), which points to the live tray object as the source of the refusal rather than anything missing in the registry. The crash also reproduces with no third-party DLLs injected into the process.

Request: Would it be possible for the reimplemented taskbar's tray object to support ITrayDeskBand (ShowDeskBand / HideDeskBand / IsDeskBandShown)? That would let legacy DeskBand apps like XMeters run their configuration UIs again. I realize DeskBands are a deprecated shell mechanism that Win11 dropped, so I completely understand if this is out of scope - but since SAB already hosts the band for display, exposing that one interface might bridge the gap.

Happy to provide crash dumps, full event-log text, or test any build. Thanks for SAB - it's what makes XMeters usable on Win11 at all.