Yes Nick you must be able to land. The point is you don't need 1.92 or 1.67 to do it.....just like every airfield you pass over within 1 hours flying distance when you go on your flight. The T/O alternate is no different you need to land ASAP hence the distance rule (not a performance rule) if you cannot return to departure airfield.
The clue is in the word DISPATCH. Dispatch requires all the regulatory extra bits and pieces..... but you cannot dispatch an engine failure. That's why you wont find any S/E performance with a factor in a QRH or OPT (Boeing) because that's all classed as ENROUTE performance. The regulator does not ask the manufacturer to produce this data so it doesn't exist. Knowing this are you seriously suggesting someone is regulatory required to get the back of a cigarette packet out and start adjusting the data to artificially increase the landing data for a T/O alternate because the incredibly expensive OPT/AFM software isn't correct ?