Feels like a few things are getting conflated.

DFU the protocol isn’t the issue — the ambiguity is around which physical port actually exposes DFU at boot, and that seems to vary by SoC variant (base vs Pro/Max), not just by chassis. The docs don’t make that distinction clear.

The fact that switching ports fixes the issue strongly suggests boot-ROM-level port routing differences. macOS wouldn’t have visibility there anyway, which explains the lack of diagnostics — but it also means the docs/UX are doing too much hand-waving.

This reads less like “DFU is broken” and more like a documentation gap that only shows up in recovery flows — exactly where precision matters most.