Do I check the box for 'preserve individual api settiings?" on Ultimate Facebook?

So I have a multi setup with subdomains, using pro sites. (www.client1.mymultisite.com)

I want upper level clients to be able to use this plugin. I am confused about the proper way to configure this plugin.

I have created an api and have it working on my main site (www.mymultisite.com) and i created another api for a client site (www.client1.mymultisite.com). Both work fine. HOWEVER- I am not sure if I need to keep creating individual api’s or is it possible to set the plugin in “network settings” in my multisite:

[from wpmu instructions: These check-boxes are your options that will determine if your subsites will use the API information you set on the Network Admin Ultimate Facebook Settings. You will need to pay special attention that you enable your sites to use the Network API in the Facebook API Settings section if you do decide to force or enable the option.]

then after, -if that is what I am suppose to do-, does each sub site just activate the ‘Ultimate Facebook’ and enter information, or do they need to also go to Facebook and create an api on their own?

Thanks in advance for any clarity on the confusion I created to myself at at this point.