Your background confuses me. Why as a 'never-Muslim' is this issue of such concern?

Such reasoning is only applicable if ʿĪsā عليه السلام had descended. If a Sat-Nav knowingly leads you to clearly the opposite direction of your destination, has it not misled you? And thus are you not misguided?

Traditional Aḥmadī theology (not today’s theology, there is a difference) makes clear that in Ahmadiyya belief 'jo Ḥaḍrat Aqdas Masīḥ e Maud عليه السلام ka tha, yani har aik shakhs jo daawat pe nahin hai aur usne mujhe qabool nahin kiya - wo musulman nahin' [Al-Fazl 12 May 1914 - Jild 1]

I accord that an Aḥmadī can be Muslim and misguided at the same time, traditional Aḥmadī theology says we’re not Muslim at all.

The qualification is necessary to establish the difference. Just as Aḥmadīs say 'non-Aḥmadī' instead of the more appropriate 'Sunnī'.

You still haven’t answered my question, Mr 'Never-Muslim'?