I've been meaning to look into that. At the moment I'm using this library as the analytics abstraction: https://getanalytics.io. I'll see if the Plausible team wants to create a plugin or do that myself when I have time.

I’ve been chatting to Marko via email and they seem very approachable!

Looks like they don't have time, but there's an open issue here: https://github.com/DavidWells/analytics/issues/96. I probably won't have time for awhile.. but on the off-chance you're interested in tackling it, I'd happily hook you up with a free Divjoy account in return ;)