From our experiences, some Fluentd users use in_tail_ex or in_tail_multiline instead of in_tail.
And for advanced use-case, some users want more rich in_tail plugin which has in_tail_ex and in_tail_multiline combination.

I think providing these features in in_tail is better for Fluentd users.
What do you think?

@yosisa
@tomohisaota