Beaming to rests over system breaks

[Mike Solomon]

Hey Lilyponders,
    Below I have two solutions to the same problem: one seems like it should
work but doesn't, whereas the other is kludgy and makes lily irate with
warnings but works.  Any suggestions for a happy medium?

\version "2.13.35"

% seems like it should work but doesn't
\score {
  \new Staff {
    \override Staff . Stem #'stemlet-length = #0.60
    \relative c' { r16 \repeat unfold 40 \times 2/3 { f8 [ r16 ] } } }
  \layout { 
    \context {
      \Voice
      \remove  Forbid_line_break_engraver
    }
    \context {
      \Staff
      \override Beam #'breakable = ##t }}}

% does work but lily doesn't like it...
\score {
  \new Staff {
    \override Staff . Stem #'stemlet-length = #0.60
    \relative c' { r16 \repeat unfold 40
       << { \times 2/3 { f8
[ \override Staff . Stem #'stemlet-length = #0.60
\once \override Voice . NoteHead #'transparent = ##t f16 ] } }
          { \times 2/3 { s8 g16\rest } } >> } }
  \layout { 
    \context {
      \Voice
      \remove  Forbid_line_break_engraver
    }
    \context {
      \Staff
      \override Beam #'breakable = ##t }}}