Yes, evidently there is a functional equivalent for Modern SharePoint Pages, Lists & Libraries.
By appending the following query string to the URL of a Modern Page, List or Library, the Page Header and Nav Bar are removed:
SP Lists Example:
SP Document Library Example:
SP Individual page example:
See Table Below
Also, there is another query string you can use to ensure that the Suite Bar is rendered, but it only works with Modern SharePoint Pages - not Lists or Libraries.
If used on Lists or Libraries in Office 365, this query string will automatically redirect the user to the Microsoft Lists Application render of the List or Library requested:
|Before ?env=Embedded in URL
||After ?env=Embedded in URL