Newbie: Merging buffer A with B using ediff-buffers

[gnuist <gnuist@protonmail.com>]

Hello emacs users,

I have a buffer A which has text lines like

text that does not contain braces but some tabs {} some more text with tabs but no braces

I have a buffer B which has text lines like

identical text to A but with ";" in place of  tabs {some semicolon containing text} some more text with ";" in place of tabs

I want to merge them as follows: I want to replace the braced text from B to A  -OR-  non-brace text from A to B, identical result.

At this moment, I do not want to use ediff-merge-buffers, emerge, smerge, etc but ediff-buffers, ediff-customize etc
to accomplish this.

This is what I have done:
I have ran this command in the main emacs window with split panes and both A and B buffers in it
and the command window pops out which toggles its size by using "?" char.
I can use "h" to rotate through various levels of highlighting.
I can use "@" and "!" to refine and also "*" for refinement.
But when I use #f to focus using a regexp {.*} for both A and B, I am not seeing any special benefit.
and when I use #h to hide  using a regexp [;]  for A and [tab] for B, I do not see any special benefit either.

I do not want to write a complicated regexp,
nor do I want to write a macro to do narrow-to-region,
nor do I want to write a complex nested regexp within a regexp
or put markers or delimiters around, as these are side-effects that require cleanup and can introduce errors.

I want to exercise all the features or as many features of ediff-buffers as possible, and if this is not possible, then can
go to other ediff-merge-... commands.
Thanks for any help.
gnuist