sh404sef and FC 1.5.6 Beta 2

more than 2 items can have same alias,
plus we would break compatibility with existing sites, that use standard joomla SEF links, and for google indexed urls too?, if we changed the urls

you mean you don't like that we prepend category-id and item-id , to the aliases ?

No this is not what I'm trying to say.
I switched off SH404sef and enabled Joomla SEF with .htaccess but without appending suffixes and now I have urls like: I'd like to have: I understand that the "home" within the url is a joomla problem and not a flexicontent-problem but why do I have the category twice, once without id and once with id?

Actually the url you provided is a little different than what you believe.
-- It is not:
domain.tld/home/catetoryalias/categoryid-category-alias/articleid-articlealias

it is
domain.tld/home/menuitemalias/categoryid-category-alias/articleid-articlealias

The menuitem alias is the first part of the url , so that joomla can identify the component that must be given the Request (this is called routing to the request to the component).

If you had no menu item pointing to the category, then you would see there some other FLEXIcontent menu item alias.

I think it may be possible to shape the URL as you need by defining mappings in the SH404 component, that are stored in the DB table,
-- but it can go wrong if ,someday, you clear these mappings, i don't remember/know too well this one.

Regards

Either way around... I suspected that this couldn't be changed the way I would like it to be -at least not without investing lots of work for a questionable effect...
So I guess, I'll stick with the default sef just the way it is. But I'll get rid of this SH404sef because as Rooney said. It creates lots of problems and the benefit is very limited...
Regards