One position does not require the parenthetical material to be followed by a further part of the host construction: an appropriate closing addition may still fall within a broad use of iʿtirāḍ. Another position reserves the term more strictly for an insertion within discourse.
The disagreement affects the relationship with tadhyīl, which commonly follows a prior statement with a reinforcing clause. Whether a given ending can carry both labels depends on how the terms are defined, not on its length.