Blog options vs site options

Hi.

As far as I understand its purpose and its design, Affiliates is a network wide plugin. That's why most of the settings are stored as site options.

So why are some still stored as blog options? I've seen 'Aff_Installed' and 'affiliate_activated_plugins' so far. Are there other ones? Is it something planned to be changed with next Pro-Sites upgrade?

Thanks.