I believe the 32-bit uses less space and you have less RAM so you have a smaller page file.
But if you have more ram, you need less of a page file.
One thing that can boost the ssd space is hibernation. The hiberfile needs to match the ram size. Unfortunately, once there, the hiberfile stays there, even if you disable hibernation. One needs to research ths to find out how to eliminate the hibernation file altogether.
I am not much in favor of micromanaging the os.
To my mind, I want the page file and index on the ssd for fast access.
A demand page fault stops the cpu dead until it is resolved, so I want that to happen quickly.
In normal desktop usage, the ssd will be long obsolete before it's quota of writes is depleted.
It is not worthwhile to try to minimize writes either.