There are some situations where intercepting/overriding SQF commands could be useful for mod teams.
I suggest allowing SQF functions to be overridden via two new commands, "override" and "callOriginal".
Overriding a function would take two arguments, a code block on the left side and a string of the original SQF function name on the right side. The code block would be passed the original left/right arguments when called normally in the future via _this as an array where index 0 is left and index 1 is right, or for functions that only take right arguments, right as index 0.
To call the original SQF function a user would pass the arguments in _this sto callOriginal on the left, and a string name of the original SQF function on the right.
Return values would be handled as with any SQF code block function.
Having looked at the way SQF stores functions internally and how the calling structure is set up this doesn't seem like it would be that overly complicated to implement.