i honestly think that the whole permanent archive idea is pointless
4chan is cool because it is extemporaneous, and sure, archives are useful sometimes like when you have find the threads you missed
but collecting every image and every post for years and years is basically throwing money away to collect tonnes of junk
a good compromise could be to archive some particular threads, like 4chanarchive did in 2010, but that's it, not everything, nobody gives a damn about the average shitty thread 5 years ago...
i'd suggest the guys who run this site to check which pages are the most visited and keep a track, i'm pretty sure than thousands of posts and images here are completely forgotten