Anyone done a fully hosted central app using this API?

Wondering if there is anyone who has actually implemented a fully hosted central application exposing no services using this API (that is using the client profiles and application client profiles) or if it is even possible? Maybe the approach of following the template projects makes no sense as the templates all produce service (peripheral) based projects. There are also no examples of such applications in the SDK and no documentation.

If someone has done it there are a few things I would like to know

1.你有到c吗reate an additional enum to describe the TASK_APP_* values for the client profiles?
2. Did you have to remove lines of code in some of the callbacks that were not 'ifdef'ed out but that were incompatible with central applications
3. How did you configure the application profile clients to work with the application
4. Did you need to do anything with the attribute database (is it needed for service discovery for example) if the central exposed no services?
5. When did you enable the application profile clients (connect first)?
6. Do you know if the callbacks block the receive thread; in other words will operations that are too long cause low level transport timeouts?

I have only gotten as far as detecting advertisements and connecting to them (after considerable sways from the documentation) but only using the limited set of callbacks provided by the template application. I have not been able to integrate any of the application profile clients (if I could get by this configuration step it should be easy to make the other profile clients into application tasks). Any information on any of these by a fellow central developer would be appreciated. This is the hardest BLE API I have ever worked with!