When I am visiting a note A, it contains links to some relevant
notes B, and the context of the link in A makes it clear why
there is a link from A to B. Thus, if there is also a link from B
to A, showing it in the list of backlink does not bring any
useful information.
On the contrary, when there is a link from B to A but no link
from A to B, it is very interesting to know this information when
visiting A: maybe we forgot to add this link in A, or maybe we
don’t want A to be too big (e.g. A describes an often used
important concept, while B describes a minor one) but sometimes
we want to know all the notes related to A.
For these reasons, I think it is more interesting to only show in
the org-roam buffer for A, the backlinks from B to A for which
there is no link from A to B.
Fortunately this can be easily achieved by modifying the function
org-roam-backlinks-get to add this line:
:and (not-in source [:select [dest] :from links :where (= source $s1)])
below the two other :and in the function.
I am curious to know if others would be interested in this
feature, and if it would be worthwile to propose it as an option
for integration in org-roam.