A lot of nonsense talked here.
The switch you cited in #7 has two positions, the centre terminal switches to either one or the other of the side terminals.
The switch ENNF cited in #12 looks the same but has a central "OFF" position in which the centre terminal switches to neither of the side terminals.
To determine its position you neither want nor need a connection for the middle position as you know it is in this position by logic when neither of the other connections is made. Just connect the centre terminal to ground and the side terminals to two inputs using INPUT_PULLUP. If one or the other input is LOW, you know the switch is turned to that side, if neither is LOW, then it is in the middle.
(If both are LOW, then something is broken! )
So you are dead wrong! That is exactly the switch you want.