It’s worth noting that the engine can readily switch between mobile and full/desktop renderers as shown and documented in Disc Jam.
Yet it doesn’t seem to have the same ability to go between SM5 deferred and SM5 forward the way Disc Jam got it to go between SM5 deferred and ES3.1 forward. SM5 forward is not implemented as an RHI, but rather as a different project mode within the SM5 RHI. (Fun thing to try: SM4 forward. None of the lights will work!)
Ultimately, there may be cases where you’d want to have both: Robo Recall lacks SSR, SSAO, distance field features, and such after all. The SM5 forward renderer may be preferred over ES3.1 since the lighting and shading look doesn’t differ as much, and because ES3.1 is missing something as basic as a dynamic spotlight which can be a dealbreaker for some games.