(matters of association bonus are probably not important for large sites)
Immediately granting association bonus carries certain risk of destructive impact (comments and votes) from users totally unfamiliar with site topics, norms and culture.
I think it makes good sense to ignore this risk at beta sites which struggle for existence and attention and are desperate for any feedback, especially positive one (upvotes).
But graduated sites have no such need in indiscriminate feedback and upvotes from passers by.
These sites have already proven their ability to sustain and have formed core groups of active users involved in maintaining and curating content. For these sites, it doesn't make sense to ignore mentioned risks.
Given above, suggest to delay granting association bonus at graduated sites until at least after 2-3 days visited. Want to participate? stick with us (for at least a day or two).
I think this would help protecting smaller graduated sites from senseless comments and upvotes of users who have no interest in longer term participation. Especially in hot questions.
Graduation, site closure, and a clearer outlook on the health of SE sites
Past experience had led us to believe that... high quality sites would always grow big and graduate. But you proved us wrong! Five years later, we have lots of tiny sites which have been in public beta for months or years, each consistently producing excellent Q&A which helps people with real problems.
The association bonus should not enable users to vote on every site
interaction between the hot questions feature and the low barrier to voting on sites where one didn't earn any reputation at all leads to a distortion of voting and dilutes the usefulness of post scores...
A Group Is Its Own Worst Enemy
Members are different than users... in all successful online communities that I've looked at, a core group arises that cares about and gardens effectively. Gardens the environment, to keep it growing, to keep it healthy... The core group has rights that trump individual rights in some situations. This pulls against the libertarian view that's quite common on the network, and it absolutely pulls against the one person/one vote notion. But you can see examples of how bad an idea voting is when citizenship is the same as ability to log in...