Thank you for answer.
My wiki is for all kind of texts, but they often consist of blocks with only 2-4 sentenses with header in each block (not ==== header, simple textual one in bold).
I can't make ==== header after every few sentences. Unordered lists for headers also looks bad, they alienate text below them.
I need to make linebreak after every header of this type. Also those 2-4 sentenses usually fill just one line if I don't use linebreaks. It looks like very irrational space distribution to me. On widescreens this single line looks unnecessary stretched.
But it really doesn't only about me and my texts, quite a lot of people want this -
http://www.dokuwiki.org/plugin:linebreak#discussion
The existence of Linebreaks and Xbr plugins also prove it. (I would also just use Xbr, but as you see I have problems with it.)
Dokuwiki is used by many types of projects with different needs, it would be great to have working easy linebreaks plugin, since it looks like popular demand.