I'm not real sure how options are stored, but the tree would flow up to 8 points instead of everything flowing up to a single point. I would think that would greatly reduce the amount of data processed per item.
This is from an earlier post from Dani Chankhour:
"If you don't want to use Inventory, then just make sure to check the Unlimited Inventory check box. If you want this checkbox always checked, then add this to your check box input field (line 477 of your product insert page):