Add a con without workaround

Author: Et7f3

rfcs/direct_call_to_external_tool.md

@@ -28,6 +28,6 @@ cons:
   - We can still read that variable and act in consequence
 
 cons without workaround:
-I don't know enough the codebase to see a big no-no
+- Unix will not be optional anymore (or maybe at least the creation part)
 
 # Unresolved questions