How about adding the ability to set the border style for the AuthForm. At times there is no reason for allowing for instance the minimize button when using it in a showmodal.
I have modified this:
function TCloudBaseWin.CreateOAuthForm(url: string;
...
begin
FOAuthForm := TForm.CreateNew(nil);
...
FOAuthForm.Position := poScreenCenter;
FOAuthForm.BorderStyle := bsDialog; //my change
...
Result := FOAuthForm;
end;