Can't enable embed_browse_spaces in new (Beta) Dashboards?

[dankurtz]

We use SSO embedding to show dashboards to some of our users. Those users have the embed_browse_spaces permission enabled in the Role they are configured with. With the regular dashboards, this works. However, when I switch the embedded dashboard URL to /dashboards-next/ to enable Beta Dashboards, the folder browser is not shown.

I see in the documentation that Beta Dashboards “do not currently support embed settings,” but this is not an embed setting, so this does not seem to be a documented limitation. Has anyone found a way to enable the embedded folder browser in the new dashboards?