When doing network mounting, or any other special mount, I would override the entrypoint with an entrypoint.sh file.
End that file with dotnet Opserver.Web.dll or whatever that command should actually be.

Do the mounting in that file, with also an error-catch, when the volume is not available for mounting.
Everything you echo or output to &1, will be shown in the container log (as long as it's no isolated process)