The narrowing logic of org-fc is unnecessarily complicated and most of it could be replaced by a org-narrow-to-subtree on the level-1 parent heading of the current card.
One issue with this is that the #+TITLE: line would not be visible anymore.
I propose showing the file title (it there is one) in the header line, replacing the review statistics currently shown there.
In the future, this would allow limiting org-mode only to the narrowed region of the buffer, greatly reducing the time required for preparing cards in large files for review.
Org-fc has two tags for controlling how cards are presented during review, :notitle: which hides the files title and :noheading: which hides the heading of the current card.
I'd like to change :noheading: so it can be attached to arbitrary parent headings, hiding them during review (useful for nested cards).
During review, the entries (section of a heading before the first subheading) of parent headings are hidden.
I'd like to add a new :showentry: tag that can be attached to parent headings, revealing their entry during review.
Cards are now reviewed by narrowing to their parent headline and file titles (if set) are shown in the header line.
This allows future performance optimizations by enabling org-mode only for the narrowed part of the buffer when reviewing large files.
Cards are now reviewed by narrowing to their parent headline and file titles (if set) are shown in the header line.
It's a huge UI improvement. You were right, the header line was filled with information we did not need.