Apply suggestions from code review

Author: ktoso

Sources/SwiftJavaDocumentation/Documentation.docc/SupportedFeatures.md

@@ -401,16 +401,16 @@ the generated box, and composite returns are not extracted.
 > Note: Downcasting returned protocol values is currently only supported in JNI mode.
 
 A value returned as `any P` / `some P` preserves its concrete dynamic type, so it can be
-recovered — the equivalent of Swift's `as?`. Every imported protocol `interface` therefore
+recovered; This is equivalent to Swift's `as?`, of a checked `instanceof` cast in Java. Every imported protocol `interface` therefore
 exposes an `as` method:
 
 ```java
 <T extends JNISwiftInstance> Optional<T> as(Class<T> type, SwiftArena arena);
 <T extends JNISwiftInstance> Optional<T> as(Class<T> type); // uses the default arena
 ```
 
-`type` must be a concrete jextracted type (a `class`, `struct`, or `enum` binding — the
-`JNISwiftInstance` bound enforces this at compile time). The cast succeeds only when the
+`type` must be a concrete jextracted type.
+The cast succeeds only when the
 value's dynamic Swift type is exactly that type, in which case you receive a fresh binding
 registered in the given arena; otherwise the result is `Optional.empty()`.
 
@@ -421,7 +421,6 @@ by a concrete `EnglishGreeter`:
 try (var arena = SwiftArena.ofConfined()) {
     Greeter greeter = MySwiftLibrary.makeEnglishGreeter("World", arena);
 
-    // Recover the concrete type — its `struct`-only members become available:
     Optional<EnglishGreeter> english = greeter.as(EnglishGreeter.class, arena);
     assertEquals("World", english.orElseThrow().getName());
 
@@ -430,9 +429,9 @@ try (var arena = SwiftArena.ofConfined()) {
 }
 ```
 
-The cast returns `Optional.empty()` — rather than throwing — whenever it cannot apply: when
+The cast returns an empty optional if the cast fails, which might happen when
 the dynamic type differs, when `type` is not a concrete jextracted type (e.g. a generic type
-or another protocol), or when the receiver is not backed by a wrapped Swift value.
+or another protocol).
 
 ### Swift closures
 

SwiftKitCore/src/main/java/org/swift/swiftkit/core/SwiftDowncastable.java

@@ -25,12 +25,12 @@
 public interface SwiftDowncastable {
 
     /**
-     * Swift {@code as?}: attempt to recover {@code type} — a non-generic concrete
-     * jextracted Swift type — from this value.
+     * Swift {@code as?}: attempt type-cast this instance to {@code T},
+     * which must be a non-generic concrete jextracted Swift wrapper type.
      *
-     * @return the recovered instance, or {@link Optional#empty()} if this value's
-     * dynamic type is not {@code type}, if this value is not backed by a Swift value
-     * (e.g. a Java-implemented conformer), or if {@code type} is not a concrete
+     * @return the type-casted instance, or {@link Optional#empty()} if this value's
+     * dynamic type is not {@code T}, if this value is not backed by a Swift value
+     * (e.g. a Java-implemented conformer), or if {@code T} is not a concrete
      * jextracted type.
      */
     default <T extends JNISwiftInstance> Optional<T> as(Class<T> type, SwiftArena arena) {