Hi Martin,
As of now, TBI is a pure SAP TM-functionality and I know of no immediate plans to bring it to a reusable layer, like Business Suite Foundation. It was designed and implemented with TM requirements in mind, and intentionally ignores some BOPF features (for performance optimization reasons). This won't be acceptable in a generally available reusable component.
For the purpose of integrating BOPF-based backend with FPM-based UIs, we already have a powerful generic engine in BS_FND - FBI (Floorplan-manager BOPF Integration), which functionally isn't at all inferior to TBI. That's why it is still used in TM (except selected use-cases, where FBI performance is not good).
FBI and TBI are intended for FPM-based UIs. However, the core of both functionalities was designed and implemented UI-agnostic - there is actually a functionality called GBI (Gateway BOPF Integration), which uses FBI artefacts (the so-called FBI views) to implement generic Gateway service. But I do not know much about it. Similarly, if the TBI implementation is written correctly, it could be used e.g. from a Gateway service implementation.
Regards,
Dragos