# Vertical spacing with outlines package

I am using the outlines package with the tufte-book class, which places footnotes in the margin. I want the first line an outline item to begin after the last line of any footnote generated by the previous item. The code below provides more details.

\documentclass{tufte-book}
\usepackage{outlines}
\begin{document}
\begin{outline}[enumerate]
\1 First item\footnote{A footnote with more than one line. Notice the horizontal location of the first sub item (item 1(a)). }
%  \vspace{12pt}%
\2 First subitem: I need to add vertical space to make this item begin after the below the last line of the footnote; you can see what I mean by exposing the command \verb!\vspace{12pt}! in the code for this example and reformatting; I would like to automate this process
\2 Some items may contain more than one \footnote{First footnote.} footnote,\footnote{An empty line follows this footnote.} or empty lines, which may further complicate incorporating automated spacing\footnote{I added a spacing command after this item.}
\vspace{5pt}%
\2 There are no spacing problems when the number of lines in an outline item is equal to or larger than those (including empty lines) in footnotes generated in the item text\footnote{A footnote after two empty lines.}
\2 So, the spacing problem only occurs when the number of lines in a footnote, or sequence of footnotes and empty lines, exceeds the number of lines in the item generating the footnote(s)
\1 In summary, I would like to automate the process of adding sufficient space (when necessary) after a current outline item-footnote pair so that the next item begins below the last line of that pair
\2 A solution requires calculating and adding the necessary space
\end{outline}
\end{document}