Can't add hyperlink button to unprotected cells in a protected sheet

I have a spreadsheet which is protected, but has a large range of unprotected cells for data entry by other users.
No matter where I try to put it, Calc will not allow a hyperlink to a document in the form of a button. I get “Protected cells cannot be modified”, even if I am trying to place the button on unprotected cells. You have to unprotect the entire sheet in order to insert a button, then protect it again.

Hyperlinks are allowed in the form of text links on a protected sheet, but a button is not.

Explanations or workarounds?

Explanation? Hmmm… Related experiences? Yes:
You cannot insert ordinary shapes into a protected sheet. You cannot even select one previously inserted. (You can activate a hyperlink assigned to it.)
A ‘PushButton’ or any form control is logically member of a form, but for the view it is associated with a shape, and the shape needs to be inserted into the DrawPage of the sheet. The drawpage obviously is locked for a protected sheet.
Well, this may have good reasons or not. I don’t know.
To learn about it you might file a bug report to
(With a quick look I didn’t find a related open bug.)