Garvin, in serendipity_event_entrysplit plugin that function only works if cut-tag placed in the extended body, not entry-body.

Hello, I didn't found the <cut> tag
I want to write all text in Entire body and place there a cut-tag, so all text after tag would writed down in "Extended body".

I mean, is there analogue of lj-tag and others? If not, read it as Feature Request :)
Thanks very much for any recommendations!