Their apis let you fetch as many pages as you want, I'm pretty sure. That's why booru clients like animeboxes and lolisnatcher can get you in excess of what you'd see on their site. You can also use a tool like gallery-dl, which is what I do, to save all the images you fetch.
On Danbooru, do you mean the loli and shota stuff? Because that's been behind a paywall since forever ago now.
What I'm more bothered about with Danbo is that only old grandfathered accounts have access to stuff that artists have specifically requested to be removed. Even if I signed up now, I wouldn't get the banned_artist stuff, which really hurts from an archiving aspect when the artist goes and wipes their pixiv too - that shit is gone forever when that happens. If you search for bad_id too, you can get a count of all the posts that they're technically still hoarding on their server but are otherwise gone forever:
>Post count for banned_artist bad_id: 12394
I just follow my favorite artists on Pixiv and Twitter and download directly from them.
I only use boorus when I want to find something specific.
I used to use Decensooru to by pass the paywall on Danbooru until the greedy bastards broke it.https://github.com/Darayavaush/decensooru
they didn't break it; it was already broken, they were just fixing the hole in their paywall.
this is pixiv's fault for having a shite UI
be sure to torrent your favorite artists on exh