It's a bit annoying that Dreamwidth won't let you browse back beyond a certain number of posts -- if I really cared, I could always use the 'Archive' links, but from memory I didn't suffer nearly so much from heat as from cold in the old days, which is why there wasn't a tag for it. (I know that in past re-tagging sprints I managed to get all the way back to 2012, so I'm paying the penalty for having become apparently more prolix as of recent years.)

I wasn't entirely surprised by hitting the limit, as I have a memory of reading in the Support Area something similar about a hardwired limit on the number of posts that can be linked to using tags -- about 500, I think. Beyond that, any earlier pages using the tag simply won't be displayed when you click on it :-(
I assume this is a hardware/resources limitation designed to simplify the task of coding the back end of the site, but it would be nice if these limits were actually a matter of public record, e.g. under 'What are tags?'