The Hub

So to get to it, first is the pickups. I plan on having a Staple P90 in the neck, a bill paisley secret agent pickup in the middle, and a normal tele pickup in the bridge. I'd like to have it wired mostly normal on a 3 way switch, where it's Neck, Neck + Bridge, Bridge. I'd also like the Neck P90 to "see" a 500k pot, and the bridge to "see" a 250k pot.

Now you may be asking where the middle pickup is here, and here's where it gets a bit weird. The secret agent pickup will be mounted under the pickguard, and wired to an on/off toggle. When off, it'll be as if it isn't there, out of the circuit. when on, it'll be on in any and all positions the selector is set to. I'd like, if possible, for this pickup to "see" 250k aswell. I just thought it'd be kinda fun to do something different, even if it's a bit nonsensical (though ive quickly become invested in this idea). How would I go about wiring this up, I'm pretty new to this kinda thing, so any help is appreciated!