When denying extented-permission-“read”-access for post (including “edit” and “delete”), this setting has no affect on logged-in users on multisite, who are not member of this specific network-blog.
All extended “read”-permissions are useless in this case.
Members of the network-blog are even getting more restricted than non-members.
As long as the frontend of the network-blog can be accessed independently of the state of being blog-member, blog-specific “read”-role-settings make no sense.
Maybe “read”-access in “extended-permissions” should be managed similar to “menu-permissisions”, which work as expected.
As long as this bug isn’t fixed I’ll have to find another workaround.

Christian