Slow response to Mpris Dbus requests

Hello,

We are working on a gnome extension to display information about media being played in the gnome panel: https://github.com/Moon-0xff/gnome-mpris-label

We noticed recently that shortwave responds significantly slower than other mpris sources, typically ~40 times slower. Which is quite problematic for the users:

As you can see above, shortwave responds in about 240ms while other sources respond in ~6ms.

We are working on ways to minimise these requests but I was wondering if there could be a bug on the app side which would explain why it’s responding so much slower than other sometimes much larger apps?