It's on the first page of Meta... It's been there for like a year at this point.
It means I need to improve my marketing

Nah it's on me. I haven't been on the forum for most of the year.
It works as good as in the past, but I've noticed a small glitch when I was counting the votes for a contest and now I've remembered to tell about it:
if I enable showing the earned merit and then I open a bigger multi-page thread all in one page ("all") - even this one - some (few) users will have nothing (no number) after "Earned Merit".
I was able reproduce this. Not sure if this is caused by slightly different layout of the "all" page and the extension is unable to figure out which users to request merits for, or if there is some sort of limit on the server side. The users that have the merit shown correctly are the ones that it has "seen" on a normal page recently, so it has their merits cached.
Edit: it's actually a bit weirder than that. I was able to get it to load all numbers after a couple of refreshes but sometimes it doesn't show even the numbers that it already has (e.g. my OP of this thread showed merits but the last post didn't).
I am one of those user! I can't see the earned merits sometimes. I have/had disabled all the userscripts, on/off'ed all the option inside the BPIP main menu, closed the tabs and reopened everything, yet it's missing. DT status is visible however.
Previously it was only on the megathreads, but now it's everywhere.
Are you also experiencing this when you click the "All" link or is this a different issue? Post a screenshot if you can.