TBH i don't see why a unified method can't be adopted. As long as it's not a requirement to have. It would make things simpler on just about every site, as each site must use a UID to identify an addon internally. I think the curse/ace-Forge packager does this already.
Something as simple as:
Code:
##Hosted-Site-ID: <Site> : <ID>
Is all it would really take, and it's not like this is going to change often if at all. IE in my own addon "Sick Of Clicking Dailies" all i'd have to add to the toc is 2 fairly static lines.
Code:
##Hosted-Site-ID-1: wowi:7798
##Hosted-Site-ID-2: curse:sick-of-clicking-dailies
It would suffice for a cursory identification.
As for Sub Modules or LoD stuff just a simple:
Code:
##Parent Addon: <AddonName>
That way the toc file for the submodules reference the parent addon that it belongs to (Distributed package wise). For addons that are modules of another but are not explicitly packaged with it won't use this. Like Grid Modules, a lot are not part of the proper Grid addon, but follow it's naming method, these packages would not use this. But Grid's naturally packaged LoD Modules would.