I'm not a pilot, just a controller. I've read every post on this. Do you think it might be expedient in the short term to do away with the "160 to 4" with a view to stabilised approach further out and at greater height ? I refer to comments about power reduction at "4" and then power demand after speed shedding.
I repeat that I'm not a pilot, but maybe ATC can help if it is considered to be worthwhile as an interim safeguard during the investigation cycle.