Cascading to list pages

I have the following folder structure:

content/foo/_index.md
content/foo/bar1/index.md
content/foo/bar2/_index.md
content/foo/bar2/something-else.md

there is a cascade in foo/_index.md

cascade:
  params:
    config:
      parameter: value

Having a layout reading out page.Params.config.parameter seems to be returning value in content/foo/bar1/index.md, but not in content/foo/bar2/_index.md.

Is there any way to have the cascade reach _index.md pages (ie. list pages) or is the cascade solely confined to single pages?

Looking deeper into this issue, I have the following frontmatter in content/foo/bar2/_index.md:

cascade:
  params:
    config:
      anotherVariable: value2

Could this override the config object from content/foo/_index.md? Is there a way to force “merging” of those cascades?

I think I might misunderstand how cascades are supposed to work.

Yes. A cascaded value will not clobber an existing value.