Hmmm.

At what point during the approach to a Black Hole, (from several million miles lets say), does one cease to be an "observer" of the Black Hole and a "test object" in the frame of reference that is "different" from an observer?

A string of cometary fragments (like Shoemaker-Levy that hit Jupiter) is falling into a Black Hole. A poor astronaut is stranded on each. Does this mean the last guy in line sees all the others sorta "cue up to fall but never do" and the first guy never sees it (the event horizon)coming?

I don't follow your logic on the "test objects' frame of reference" never being able to see the event Horizon. If this test object never sees it before falling thru, (but an observer does), than at some point on approach it would have had to cease to be visible, based on some as yet undetermined value that would describe just where this occurs.

This is all very highly speculative ANY way you look at it since we have no opportunity to truly test what we THINK MAY happen based on the math alone.