With 'Hide Toolbar on Scroll' option ON we have:

No toolbar visible until you scroll up.
With 'Hide toolbar' tap from menu we have:

Both toolbars visible (bad) but both are sitting still, no flickering (good). The problem: manual several taps on every page. Another problem: toolbar are eating valuable screen space for no good.
I’m proposing to make another option: Something like 'Total fullscreen mode' And hide both toolbars until tap in the center, like book reader apps are doing.

Ideally for me: is modification of the 'Hide Toolbar on Scroll' option so it really does hide until tap in the center.