Is there any drawback with such a simple design? Could we for example
use char number 1? It should be very easy to implement for w32 and the
other case above (where char 1 is just replaced with & and the other
case where it is replaced with _).
I haven't followed this. But I would be against having any (printable)
character in a menu-item name be interpreted specially and not just treated
as part of the name. It is not the case that some (printable) character
"could not possibly be part of the title" - whatever (printable) character
you choose, someone will want to use it in a menu item. `_' can certainly be
useful in a name.