You can do this right now.
Your suggestion is wrong, but, your question is right.
It cannot be done per object as that would allow an object on one plate with and one without vase mode enabled.
The solution is to do it on the plate level, which they have.
You can access this option from two locations.
- The nut icon (used to be a cog) attached to the right of each plate
- In the objects view, select the plate NOT an object
In each case, enable the Spiral vase option for the plate you wish it to be used on and disable it for all other plates.
In reality, it is disabled by default, so enable it on the plate(s) that require it.
Remember, the spiral mode works with a single object per plate.