That last option doesn't sound like it would be good to me.
I'm spoiled now from the stacked V/T pots on my VM Jaguar, and I cannot see that pushing both p'ups through the same TONE pot.
With them both individually TONE adjustable I get both grunt and growl with a P-p'up in Super LOW and the J-p'up in Super HIGH at the same time and just bring in the VOL as necessary.
I think my SR500 would be mucho better if I could separately address each soapbar with independent TONE and VOL and not have to blend them with the PAN from Bridge to Neck.
As much as I love my SR, I really like the separate tune-ability of the VM Jag a little better with it's V/T-V/T stacked pots - but they are different instruments and both stand alone as great in my ears and eyes.
I hope I stated that in a clear-enough way, since I haven't had my medications yet this AM.