Would we be able to accept a separate intermediate_storage_def argument here instead and follow this branch if that argument is given?

The caller of this function has the mode, right? And the mode knows whether there's a single or multiple intermediate storages, based on the criteria above?

So would we be able to pass something in here that ? Then we wouldn't need to rely on the string matching, which would be fine in many situations, but is a little scary.

Could we set the name to None in this branch and, in context_creation_pipeline.intermediate_storage_def_from_config, which is I think the only place this gets used, do something like the following:

if mode_definition.intermediate_storage_def:
    return mode_definition.intermediate_storage_def
else:
    # everything else that's currently in that function

hmmm, we could, yes

So, to be fair about the string matching being scary, a _ton_ of other places require this top-level string to be config, which is why I felt safe doing it. The reason I didn't want to test for single mode is I didn't want to _make_ people not use their storage name/edit their runconfigs even when they switched to a single intermediate_storage_def

None has a special meaning in IntermediateStorageConfig, unfortunately (it generates config for the default, which is in_memory)