If you use a high resolution screen maybe you need to patch dwm to allow more characters like this patch https://gist.github.com/edvardxyz/598417868b38662d171398f374e8af32
edvardxyz/Tabs-in-title
Firefox tabs in title, intended for firefox in kiosk/full-screen mode with dwm. With this extension you can see your tabs in the dwm bar.
JavaScriptWTFPL