Hi,
I use the following, very dirty solution. Given an arbitrary chord, for instance <c e g c> on a 4/4 time signature:
\version "2.19.83"
\relative c'{
\time 4/4
\override NoteHead.font-size=#-100
s2.. <c e g c>1*1/8 ~
<c e g c> s2..
\revert NoteHead.font-size
\unHideNotes
}
The extremely reduced font size stands for the equal size of the ties. Otherwise they would have very different sizes.
Hope there are better solutions or more comprehensive ones.
Regards,
F.