Hi Sergey,
I did it

and it's already in FLEXIcontent's component. Have a look to component/com_flexicontent/librairies/jcomments
The plugin is in the folder. It's automatically added to Jcomments plugin folder if not already inside, but it will be of course better if it's directly in your component.
I should contact you for a long time already, but I'm always in a hurry (Eric Lamy gave me your email).
Just advise me if you put it in your next release.
If we could enhance the support beetween our two components if would be great (eg comment count in the items view, access to comments on each item).
We definately follow the same philosophy in terms of flexibility and integration to the existing systems and it should be cool to enhance the concept :-)
Cheers,
Emmanuel.