Yet more edits.

README.md

@@ -482,10 +482,10 @@ JMustache is internally thread safe with the following caveats:
     one another, they'll simply both resolve the variable instead of one resolving the variable and
     the other using the cached resolution.
 
-So the executive summary is: as long as all helper classes you supply are thread-safe, it is safe
-to share a `Mustache.Compiler` instance across threads to compile templates. If you pass immutable
-data to your templates when executing, it is safe to share a `Template` instance across threads,
-with multiple threads executing the template simultaneously.
+So the executive summary is: as long as all helper classes you supply are thread-safe (or you use
+the defaults), it is safe to share a `Mustache.Compiler` instance across threads to compile
+templates. If you pass immutable data to your templates when executing, it is safe to have multiple
+threads simultaneously execute a single `Template` instance.
 
 Limitations
 ===========