wow, this split header is very nice! cool feature indeed.
And whats more, it opens up space for a cool marquee which we could template with the latest news, or alerts, or what have you. I could imagine it to show the notifications it now sends out, or even show conditional icons based on these alerts. Or, well, options galore.
Might be a nice feature request for 2020 
Marquee support in split mode.
one small error in the log:
/local/lovelace/resources/custom-header.js?v=1.1.5:576:26048 Uncaught TypeError: Cannot read property 'split_mode' of undefined
though I can’t see anything resembling an issue…