convert to smart object resolution problem

Hi,

I'm working for video game UI and because of that, my photoshop documents always need to have a resolution of 72 ppi.

My current problem is that when i convert some layers to a smart object using the "convert to smart object" rollout menu, Photoshop always gives this new file a resolution of 300 ppi.

This is very anoying and i don't find in the preferences a way to set a specific resolution for smart object.

Changing the resolution after the creation of the smart object is not a solution (it's a slow process i need to repeat each time a new smart object is create and the smart object became larger in the parent document)

Create a new document with a specific resolution and drag it as a smart object to my parent document is also a very slow process i cannot use as my work files contains a lot of thoses smart objects.

So is there a solution, i'll be very happy to know.

Thanks !