2-channel originated as a website of anonymous bulletin boards.
Looks like you consider the desirable policy for 2-channel users
would be to put quality before quantity. But even the concept of ID
was absent in 2-channel at first.
To be sure, your policy may raise its quality, but even good-natured
users will probably get tired of it because of its discomfort
and leave.
The beauty of 2-channel is noise. Out of all that noise, users are
supposed to discover useful information, saying "This post may be
stating the truth!" or "This comment is interesting!" That's precisely
the joy of 2-channel. I hope you'll realize that SLIP is a risky
function that will cause even those good old posters from 2-channel.