Surface Duo 2 stuck in Qualcomm EDL mode (9008) — requesting the Microsoft-signed Firehose programmer

Device: Microsoft Surface Duo 2 (model 1968, codename "zeta", Snapdragon 888 / SM8350)

My Surface Duo 2 will not boot to Android, fastboot, or recovery. It is stuck in Qualcomm Emergency Download (EDL) mode and enumerates as Qualcomm HS-USB QDLoader 9008 (VID 05C6 / PID 9008). The screen stays black. This happened after a third-party firmware configuration tool modified the boot configuration.

Technical details (read from the Sahara hello packet using github.com/bkerler/edl):

• HWID: 001350E100690044
• MSM HW ID: 0x1350E1 (SM8350 / Snapdragon 888)
• OEM ID: 0x0069 (Microsoft) / Model ID: 0x0044
• OEM PK Hash: 9671F3D6922201ED2E8EAF18B66067650595594E06B4147D31C943B417585DAB202CC0C384D724FB02A80DA37CFBE3A1 ("Microsoft Corporation, Andromeda Attestation PCA 2017")

Because the device cannot reach fastboot or recovery, the only recovery path is flashing over EDL, which requires the device-specific Qualcomm Firehose programmer signed with Microsoft's Andromeda key. No generic SM8350 loader will work, because the signature must match the PK hash fused into this device. Without the correctly signed programmer, the device is unrecoverable by the user.

I am requesting any one of the following:

1. The Microsoft-signed EDL Firehose programmer for the Surface Duo 2 (zeta), so I can reflash it myself with QFIL or qdl; or
2. A remote/supervised flashing session, or the procedure a Microsoft service center uses for a Duo 2 in 9008 mode; or
3. The out-of-warranty exchange options and cost.

I own this device outright, I am the original owner, and it is not carrier-locked or reported stolen. I am experienced with Qualcomm flashing tools and only need the correctly signed programmer.