I don’t think SSR is on the current roadmap for Epic since there are hardware limitations that make the implementation of this feature unfeasible at this time.
The only advice I can give is to continue trying to work with other reflection capture actors or fake it by projecting a cubemap onto the surface of your meshes via a material (reflection map). This is pretty old school but is better than nothing. The trade off is the “reflection” isn’t captured at runtime and is therefore static (not sure if this is an acceptable trade off).
If you need real time captures keep trying to work with planar reflections as that may be your best choice for something like a river.