There's a reasonable argument for moving to 64-bit on security grounds too. The increase in virtual address space makes ASLR far more effective since there are many more options for positioning compared to 32-bit code. On top of that, any attacks are more likely to hit a unallocated page as opposed to anything useful (with some limitations of course).
You can do that easily enough as it is. One way is to set up multiple SSIDs per radio with separate PSKs. Another way is to use WPA2 Enterprise with one username/password pair per device.
To spot the expert, pick the one who predicts the job will take the longest and cost the most.