Hi Elliot, just checking in to see if you have an update on this issue.
As a refresher, the current version of ACF will delete backslashes in any wysiwyg field upon saving. This issue exists because the ACF codebase has an extra call to stripslashes_deep() to deal with old PHP versions running magic quotes.
In my case, this destroys LaTeX markup in those fields, because every LaTeX variable starts with a backslash. Others have chimed in saying that their regular expressions get mangled.
Your proposed solution seems fine to me. More details on it in your comment here:
http://support.advancedcustomfields.com/forums/topic/regression-backslashes-stripped-in-wysiwyg/#post-4335
Thanks!
