New methods in nsIRDFContainer

I'm trying to make paste in Mozilla's bookmark manager faster than
O(n^2) <https://bugzilla.mozilla.org/show_bug.cgi?id=287392>. Quite
some time is spent in RDFContainerImpl::Renumber() which gets called
for every single pasted bookmark by
RDFContainerImpl::InsertElementAt(). If Renumber() was public, it
could be called once for all new bookmars to be inserted and then
InsertElementAt() could be called with aRenumber set to false.
My question now is if I may simply add a method for re-numbering or
methods for inserting/removing multiple elements at once in
nsIRDFContainer.

Thx,
   Jan