FrontEnd Item Form and Combo Primary/Secondary Categories

Hello everyone, I wanted to ask a question:
I have three categories (hierarchical) so made​​:

Cat 01
____ Cat 01.01
________ Cat 01.01.01

I would like to allow from FrontEnd Item Form in the selection lists of categories (Combo Primary and Secondary), choosing only the third category (Cat 01.01.01) and not the other two.
I tried with the ACL settings but not allow me to have a configuration of the type (Conflicts):

Cat 01 (Create = Off)
_____ Cat 01.01 (Create = Off)
_________ Cat 01.01.01 (Create = On)

A trick would be to use more menu items (one for each group) with ad hoc set attributes in the tab "Category ACL" but I want to know if there is a mode more "clean" this because I have many groups.

Thank you in advance.

Dario

Hello

making some categories not selectable is not supported by Joomla nor by FLEXIcontent

but i clearly see the usefulness of this ...

indeed this would be an interesting feature, and it can be done via a parameter:

-- "category assignable to items"

will do in future version,

now it is not available

Regards

Hello George,
thank you for understanding of necessity. With regard to the parameter perhaps (but to check) if possible, attach it directly to the user (group or author or both in hierarchy) might be even more powerful.
In any case I will wait for the next version.
Thank you again.
Dario.