Support for Max View Distance Override and Custom Near Clipping Plane for orthographic Scene Captures has been implemented and will be available in patch 5.8.2.
CL 54364188 was the original, but CL 56298151 was an integration edited version for Release with a minor improvement to avoid a potential divide by zero in degenerate cases, and would be the preferred version if you are manually integrating. The updated version made it back to the main branch as of CL 56298304, and was integrated to UE5 Release 5.8 as CL 56699511.