RTL altitude climb

When flying in a mountainous area it is critical for safety to have RTL altitude set high enough unless we have other safe RTL feature. But not only RTL altitude is critical for safety but also a way UAV will climb to that altitude in a mountain area. It may be unsafe to climb on route to Home position but better to climb with Loiter_to_Alt mode.

Is it a good idea or there are disadvantages in such a behavior? It may be optional of cource.