I think it's definitely doable, since Pump.io allows "remote login", and has a pretty good API. But of course, this would require work on the blog side.

We can look at OpenFarmGame as an example of something that's not really a Pump client in the traditional sense, and uses your Pump.io account from your server to login to the game. And it's a web app, meaning that this fits the website usercase, not just desktop or mobile clients =)

» Splicer:

“[...] he problem I've encountered being unable to reply to a notice that existed before I followed the poster of the notice. [...]”

That still happens, AFAIK, but I should point out that the problem only happens if nobody on your server followed that user yet, not you personally.

So, if userFrom2016@datamost.com follows you, newUserSept2017@datamost.com who just registered right now, will be able to comment on most of your previous posts.

This is obviously a much bigger problem if you're the only user on your server, of course (for the reverse case) xD