diff --git a/clients/session/Cargo.toml b/clients/session/Cargo.toml
index e57559ef..c4cc7ec2 100644
--- a/clients/session/Cargo.toml
+++ b/clients/session/Cargo.toml
@@ -27,9 +27,13 @@ ui = ["dep:pf-console-ui", "dep:serde_json"]
 # Same Linux+Windows gating as the rest of the client stack; elsewhere this is a stub
 # binary.
 [target.'cfg(any(target_os = "linux", windows))'.dependencies]
-pf-presenter = { path = "../../crates/pf-presenter" }
+# `default-features = false` on both: THIS crate's `pyrowave` feature (above) is the single
+# switch that turns the wavelet codec on, and it enables it explicitly on each. Inheriting their
+# defaults instead would make `--no-default-features` a lie — the Windows ARM64 leg builds that
+# way precisely to skip the vendored PyroWave C++, which has no ARM64 SIMD path.
+pf-presenter = { path = "../../crates/pf-presenter", default-features = false }
 pf-console-ui = { path = "../../crates/pf-console-ui", optional = true }
-pf-client-core = { path = "../../crates/pf-client-core" }
+pf-client-core = { path = "../../crates/pf-client-core", default-features = false }
 punktfunk-core = { path = "../../crates/punktfunk-core", features = ["quic"] }
 # The fake-library dev hook (`PUNKTFUNK_FAKE_LIBRARY`, browse mode) parses GameEntry JSON.
 serde_json = { version = "1", optional = true }
diff --git a/clients/windows/Cargo.toml b/clients/windows/Cargo.toml
index af6d3960..0114c7a4 100644
--- a/clients/windows/Cargo.toml
+++ b/clients/windows/Cargo.toml
@@ -29,7 +29,17 @@ punktfunk-core = { path = "../../crates/punktfunk-core", features = ["quic"] }
 # The shared client service layer: the trust/settings stores (ONE `Settings` struct for the
 # shell and the spawned session binary — src/trust.rs re-exports it) and the game-library
 # data model (fetch + art pipeline) behind the library page.
-pf-client-core = { path = "../../crates/pf-client-core" }
+#
+# `default-features = false` drops pf-client-core's default `pyrowave`, which would otherwise
+# build the vendored PyroWave C++ INTO THE SHELL — dead weight here (the shell never decodes;
+# it only offers "pyrowave" as a codec preference string the session binary acts on) and fatal
+# on ARM64, where Granite's math falls back to x86 SSE intrinsics and stops at
+# `simd.hpp: #error "Implement me."`. This does NOT drop PyroWave from the Windows client:
+# decode lives in the spawned punktfunk-session binary, whose own default enables the feature,
+# and cargo's feature unification turns it back on for the shared pf-client-core whenever that
+# binary is in the same build (x64). On the ARM64 leg both are built --no-default-features, so
+# nothing enables it and the C++ is never compiled.
+pf-client-core = { path = "../../crates/pf-client-core", default-features = false }
 
 # WinUI 3 UI via windows-reactor (a declarative React-like framework backed by WinUI). Its
 # `build.rs` downloads the Windows App SDK NuGets and stages the bootstrap DLL + resources.pri
diff --git a/clients/windows/packaging/AppxManifest.xml b/clients/windows/packaging/AppxManifest.xml
index dc1c9de7..a713bf56 100644
--- a/clients/windows/packaging/AppxManifest.xml
+++ b/clients/windows/packaging/AppxManifest.xml
@@ -59,9 +59,14 @@
     </Application>
     <!--
       Second entry point: the couch/console UI, for an HTPC or a TV-attached box where the
-      desktop shell is the wrong first screen. Same full-trust executable, launched with
-      `--console`, which hands straight off to the session binary's controller-driven
-      browse mode (host list, pairing, settings, library) fullscreen.
+      desktop shell is the wrong first screen. Its own executable (punktfunk-console.exe)
+      because an MSIX Application entry cannot pass arguments to a full-trust exe; it hands
+      straight off to the session binary's controller-driven browse mode (host list,
+      pairing, settings, library) fullscreen.
+
+      NOTE: never write a double hyphen in this file. XML forbids it inside a comment, and
+      makepri rejects the whole manifest ("Appx manifest not found or is invalid") — which
+      is exactly how the console flag spelled out here broke the v0.15.0 MSIX build.
     -->
     <Application Id="PunktfunkConsole" Executable="punktfunk-console.exe"
                  EntryPoint="Windows.FullTrustApplication">
diff --git a/crates/pf-presenter/Cargo.toml b/crates/pf-presenter/Cargo.toml
index 7c2e3ad3..a98156c6 100644
--- a/crates/pf-presenter/Cargo.toml
+++ b/crates/pf-presenter/Cargo.toml
@@ -11,7 +11,11 @@ repository.workspace = true
 # Same Linux+Windows gating as the rest of the client stack (dmabuf import is the one
 # Linux-only module — see lib.rs).
 [target.'cfg(any(target_os = "linux", windows))'.dependencies]
-pf-client-core = { path = "../pf-client-core" }
+# `default-features = false`: the PyroWave decode backend is turned on through THIS crate's own
+# `pyrowave` feature (which re-exports it below), never by inheriting the dependency's default.
+# Otherwise a consumer that deliberately builds us without `pyrowave` still drags the vendored
+# C++ in — fatal on Windows ARM64, where Granite has no SIMD path.
+pf-client-core = { path = "../pf-client-core", default-features = false }
 # AVVkFrame access (Vulkan Video frames: live sync state under the frames lock).
 pf-ffvk = { path = "../pf-ffvk" }
 punktfunk-core = { path = "../punktfunk-core", features = ["quic"] }