The Rav4 has the same engine as the NX, different to the IS with less power.
The hybrid systems are essentially the same for Toyota and Lexus, but the tools that Toyota dealers use are normally restricted to just working on Toyota models, only if they also have a Lexus franchise to their get those vehicles unlocked.
The dealership isn't underwriting the hybrid health check, it is Toyota GB (for both Toyota and Lexus), and so if a Toyota dealer performs an unofficial hybrid health check and you have a problem then your claim may be rejected.