I've given mobile navbar some more thought. Welcome to Navbar 3.1 for mobile: now with swipe chevrons and better previous/next spacing, but without up arrows anymore because they couldn't be made to fit. Also a completely different login bar which will pop up dialogues because the more desktop-like one simply did. not. work. and never would. BUT: it's zero additional clicks as specced.
Also posted to ソ-ラ-バ-ド-のおん; comments at Dreamwidth. Please comment there.