Not an ideal solution but any scripts you place into the /etc/cron.d/ | /etc/cron.hourly|daily|weekly|monthly will survive a reboot (they live on the readonly part of the installation).

ie,

  voyage#> remountrw
  voyage#> nano -w /etc/cron.daily/i_want_this_to_run_each_day.sh
  voyage#> remountro