when we upgrade to vb3 we have to rewrite the whole system, then it won't show up anymore to others than the author (and of course the user who has installed it )
I think that the creators of the hack should be able to see who has installed the hack. They've taken the time and effort to create it 'free of charge' and the least people could / should do is show their appreciation - by both clicking on the 'Install' button and also in a reply post.
I can't see why showing it on the postbit would be that advantageous as people can already see this information elsewhere. I've therefore voted for the second option.