Created attachment 104612 [details] Screenshot with the less than stellar spacing ;-) For some sizes of the panel, the time widget has insufficient spacing at the bottom.
No margin between digital clock and screen edge at certain panel height - long date enabled
Created attachment 109312 [details] no-margin-long-date Distribution: KDE neon Developer Edition - Stable Branches Plasma: 5.11.4 Frameworks: 5.41.0 Qt: 5.9.3 Kernel 4.10.0-40-generic
seems related to https://bugs.kde.org/show_bug.cgi?id=367809
After upgrading to Plasma 5.12 I have a similar problem. In my case the text is slightly too high, but not for all panel heights. This issue did not exist before Plasma 5.12 for me, so I'm not sure it's the same bug.
This should be fixed now in at least Plasma 5.19, and possibly also 5.18.
I can confirm, that this no longer happens in 5.19. Thanks for your work!
You're welcome!