I can see that DOS applications might require Virtual 8086 mode, but from what I can tell, almost no Win16 applications require it nor require hardware task man

I can see that DOS applications might require Virtual 8086 mode, but from what I can tell, almost no Win16 applications require it nor require hardware task management (I'm not even sure I'm aware of any application that uses hardware task management!). Granted, Win16 is not an especially long period of active application development, but I would expect that the vast majority of Win16 applications would work perfectly fine in x86-64 compatibility mode. I know that the ones I have played with do.