diff --git a/.mozconfig-aarch64-apple-darwin b/.mozconfig-aarch64-apple-darwin
index 6a14087c0b4c..10861822461f 100644
--- a/.mozconfig-aarch64-apple-darwin
+++ b/.mozconfig-aarch64-apple-darwin
@@ -18,7 +18,11 @@ unset MOZ_STDCXX_COMPAT
 
 if test "$WFX_RELEASE"; then
     ac_add_options --enable-lto
+    ac_add_options --enable-optimize="-O3 -mcpu=apple-m1 -w"
     ac_add_options --enable-release
+    ac_add_options --enable-rust-simd
+    ac_add_options RUSTC_OPT_LEVEL=3
+    export RUSTFLAGS="$RUSTFLAGS -Ctarget-cpu=apple-m1"
 fi
 
 ac_add_options --disable-crashreporter
@@ -39,8 +43,6 @@ elif test -f "$HOME/.mozbuild/sccache/sccache"; then
     ac_add_options --with-ccache=$HOME/.mozbuild/sccache/sccache
 fi
 ac_add_options --enable-install-strip
-ac_add_options --enable-optimize="-O3 -mcpu=apple-m1 -w"
-ac_add_options --enable-rust-simd
 ac_add_options --enable-strip
 ac_add_options --enable-updater
 
diff --git a/.mozconfig-x86_64-apple-darwin b/.mozconfig-x86_64-apple-darwin
index 42a4907c2d48..6dd3971af104 100644
--- a/.mozconfig-x86_64-apple-darwin
+++ b/.mozconfig-x86_64-apple-darwin
@@ -18,7 +18,11 @@ unset MOZ_STDCXX_COMPAT
 
 if test "$WFX_RELEASE"; then
     ac_add_options --enable-lto
+    ac_add_options --enable-optimize="-O3 -march=nehalem -mtune=haswell -w"
     ac_add_options --enable-release
+    ac_add_options --enable-rust-simd
+    ac_add_options RUSTC_OPT_LEVEL=3
+    export RUSTFLAGS="$RUSTFLAGS -Ctarget-cpu=nehalem"
 fi
 
 ac_add_options --disable-crashreporter
@@ -39,8 +43,6 @@ elif test -f "$HOME/.mozbuild/sccache/sccache"; then
     ac_add_options --with-ccache=$HOME/.mozbuild/sccache/sccache
 fi
 ac_add_options --enable-install-strip
-ac_add_options --enable-optimize="-O3 -march=nehalem -mtune=haswell -w"
-ac_add_options --enable-rust-simd
 ac_add_options --enable-strip
 ac_add_options --enable-updater
 
diff --git a/.mozconfig-x86_64-pc-linux-gnu b/.mozconfig-x86_64-pc-linux-gnu
index 66c221663d58..ff52cf470496 100644
--- a/.mozconfig-x86_64-pc-linux-gnu
+++ b/.mozconfig-x86_64-pc-linux-gnu
@@ -11,7 +11,11 @@ fi
 
 if test "$WFX_RELEASE"; then
     ac_add_options --enable-lto
+    ac_add_options --enable-optimize="-O3 -march=core2 -mtune=haswell -w"
     ac_add_options --enable-release
+    ac_add_options --enable-rust-simd
+    ac_add_options RUSTC_OPT_LEVEL=3
+    export RUSTFLAGS="$RUSTFLAGS -Ctarget-cpu=core2"
 fi
 
 ac_add_options --disable-crashreporter
@@ -31,9 +35,7 @@ elif test -f "$HOME/.mozbuild/sccache/sccache"; then
     ac_add_options --with-ccache=$HOME/.mozbuild/sccache/sccache
 fi
 ac_add_options --enable-install-strip
-ac_add_options --enable-optimize="-O3 -march=core2 -mtune=haswell -w"
 ac_add_options --enable-pulseaudio
-ac_add_options --enable-rust-simd
 ac_add_options --enable-strip
 ac_add_options --enable-updater
 
@@ -50,7 +52,6 @@ if test -f "$PWD/mozilla-api"; then
     ac_add_options --with-mozilla-api-keyfile="$PWD"/mozilla-api
 fi
 
-export RUSTC_OPT_LEVEL=2
 export MOZ_INCLUDE_SOURCE_INFO=1
 mk_add_options AUTOCLOBBER=1
 MOZ_REQUIRE_SIGNING=
diff --git a/.mozconfig-x86_64-pc-windows-msvc b/.mozconfig-x86_64-pc-windows-msvc
index 635607cb3ae6..a1c94f9f0704 100644
--- a/.mozconfig-x86_64-pc-windows-msvc
+++ b/.mozconfig-x86_64-pc-windows-msvc
@@ -14,7 +14,6 @@ export HOST_CXX="$HOME/.mozbuild/clang/bin/clang++"
 export MIDL="${TOOLS}/wine/bin/widl"
 export MOZ_INCLUDE_SOURCE_INFO=1
 export MOZ_STUB_INSTALLER=1
-export RUSTC_OPT_LEVEL=2
 export WIN32_REDIST_DIR="${TOOLS}/visual-c/redist/msvc/${MSVC}/x64/microsoft.vc143.crt"
 export WIN_UCRT_REDIST_DIR="${WINDOWSSDKDIR}/redist/${WSDK}/ucrt/dlls/x64"
 export WINE="${TOOLS}/wine/bin/wine64"
@@ -26,7 +25,11 @@ mk_add_options "export PATH=$EXTRA_PATH$PATH"
 
 if test "$WFX_RELEASE"; then
     ac_add_options --enable-lto
+    ac_add_options --enable-optimize="-O2 -Qvec -w -clang:-ftree-vectorize -clang:-march=core2 -clang:-mtune=haswell"
     ac_add_options --enable-release
+    ac_add_options --enable-rust-simd
+    ac_add_options RUSTC_OPT_LEVEL=3
+    export RUSTFLAGS="$RUSTFLAGS -Ctarget-cpu=core2"
 fi
 
 ac_add_options --disable-bits-download
@@ -48,8 +51,6 @@ elif test -f "$HOME/.mozbuild/sccache/sccache"; then
     ac_add_options --with-ccache=$HOME/.mozbuild/sccache/sccache
 fi
 ac_add_options --enable-install-strip
-ac_add_options --enable-optimize="-O2 -Qvec -w -clang:-ftree-vectorize -clang:-march=core2 -clang:-mtune=haswell"
-ac_add_options --enable-rust-simd
 ac_add_options --enable-strip
 ac_add_options --enable-updater