This gives you all 5 original positions.
And mini toggle would give you 2 extra: neck + bridge , and all 3 pickups.
I've seen people did get it in that way.
So if you are on like:
Neck + middle .... So in 2nd. If you add mini toggle for bridge, you will get all 3.
Or if you are on neck only, and add toggle on bridge, in 1st would give you neck + bridge.
But the trick is: you need to decide if you want that mini toggle on bridge or neck. You can get it on 1 pickup only.
Pretty much like Stratocaster tone pots.
You can either get it for like bridge, and other for neck and middle.
Or you can get it for middle, and other for neck and bridge.
So you can get like, difference in sound based on different pot values. FE bridge tone pot on 10, middle tone pot on like 6. And together you get that something not regular.
Same with this mini toggle.
You are either like, all time on bridge. In that case you kinda do add mini toggle to on/off neck one.
Or if you are more on neck, add mini toggle on bridge ......
Deprends what is more practical for you.
If I would kinda play clean more, I would put it on bridge.
And if I played dirty more, I would put it on neck.
But you need to decide for yourself.
Cause you can't like put 2 mini toggles both on neck and bridge.