fetching http counts after installing SSL?

I’m preparing to migrate a website to SSL and am seeking some info about the “Fetch the share counts from HTTP url as well?” plugin option. I’d like to know:

1. When I enable the “Fetch HTTP counts” option, will this *reliably* fetch the share counts from *both* the legacy HTTP and new HTTPS URL’s from Facebook, Twitter, LinkedIn, and Google+?

2. Is there anything else I need to do, or be aware of, besides enabling the “Fetch HTTP counts” option?

Thanks in advance for any advice you can offer! ??