Hi. Thanks for your interest !
First and quick answer: because even if I included other themes, I only modified (by hand) the Bootstrap, Cyborg and United themes in my fork. The answer is simple, my fort is mainly here for personal use, not meant to be widely used by many others, and I love United (Ubuntu-like theme). My clone fork on GitHub has the same issue... Sorry.
So in fact, I am not really "keeping Strapdown.js going". The original repo is well designed to be able to modify it, recompile it and distribute it efficiently. Mine is not, sorry...
I encountered strapdown-topbar a whileago, and it is indeed interesting.
I am not sure how you would like me to help? Regards.
Sorry, it's not that easy. I suggest that you use the original strapdownjs and not my fork. Regards