hmmmm, I just grabbed my caliper and checked the next best micro-USB plug: ~1.9mm high. Maybe placing an additional micro-USB into spacer frame isn't that bizarre an idea after all, though it for sure not been what I initially thought of.
What I evidently thought of quite some time ago been to put an additional SIM slot-in tray on the spacer frame (alas for now we don't see much use in that, due to modem not supporting multi-SIM). So I should get used to that concept, no matter what the particular component/function, be it a SIMslot or a connector.

Now for the bad news: I couldn't find suppliers for the ANX7805

/j