I don't know if this is quite yet at a "cavalry" point (because no one has answered, yet). https://www.excelforum.com/excel-for...r-columns.html
My reaction to the OP's mockup tables is that they look exactly like pivot tables, using QUARTILE() functions instead of the usual SUM/COUNT/AVERAGE/... functions that are readily available in the PT options. Obviously, a QUARTILE(IF(...)...) array function should be able to work. Before suggesting that, though, I was hoping someone could tell me if it is possible to do this using a pivot table instead.