Hi @frob ,
Here is no available OOTB way to create a pure blank page. You could copy "Home" page and then delete all web part as a workaround.
1.Copy "Home" page.
Site contents > Site Pages > select "Home" page > Copy to > Copy here
2.Now you can find a new page named "Home1", edit this page and delete all web part.
My test result:
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