However many engines there are in the tail, will we ever see todays huge diameter turbofans mounted that way in a future airliner? Mounted close to the fuselage and back far enough so that their thrust lines could be canted towards the CG, the tailpalne issues would be much reduced; except maybe getting a rough time from reverse thrust and then there's the worries about rubbish thrown up from the main gear and water ingestion. I suppose mid-mounted engines something like a scaled up A10 Warthog, so that the wing (swept though) would provide a shield.
If we are stuck with under wing pylon-mounted engines as in all current designs, I wonder why twin Vertical Stabs fitted to the end of the HS are not more popular? They seem to work very well for the Antonov 225 and I think they look very good. I realise that in this case, the reason behind the design, was to put the VS in clean airflow when carrying external loads on top of the fuselage, but this configuration would seem to have a lot to offer in engine out/exterme conditions that might come close to overloading a single cantilevered fin.
Mounted at about their midpoint to the HS, the rudder forces would be a straight push/pull with little bending moment, and I would have thought that being downstream of the engines (but not too close), they would benefit from the increased local flow velocity to enhance rudder authority in low speed/high thrust situations and they wouldn't be masked by the fuselage at high AOA. I suppose that they may work out heavier, which wouldn't please the "beancounters", but you can tell them that their expensive new hangers wouldn't need to be so high and there's plenty of vertcal billboard area to paint their Logo on!