diff --git a/include/core/SkSpan.h b/include/core/SkSpan.h
index b09ec867a0..9487e9e222 100644
--- a/include/core/SkSpan.h
+++ b/include/core/SkSpan.h
@@ -33,11 +33,8 @@ public:
     constexpr SkSpan(const SkSpan<U>& that) : fPtr(that.data()), fSize{that.size()} {}
     constexpr SkSpan(const SkSpan& o) = default;
 
-    constexpr SkSpan& operator=(const SkSpan& that) {
-        fPtr = that.fPtr;
-        fSize = that.fSize;
-        return *this;
-    }
+    constexpr SkSpan& operator=(const SkSpan& that) = default;
+
     constexpr T& operator [] (size_t i) const {
         SkASSERT(i < this->size());
         return fPtr[i];
diff --git a/src/core/SkPaintParamsKey.cpp b/src/core/SkPaintParamsKey.cpp
index 460b65fad2..0e5f4a64ba 100644
--- a/src/core/SkPaintParamsKey.cpp
+++ b/src/core/SkPaintParamsKey.cpp
@@ -58,7 +58,6 @@ void SkPaintParamsKeyBuilder::beginBlock(int codeSnippetID) {
 
     SkASSERT(!this->isLocked());
 
-    fData.reserve_back(SkPaintParamsKey::kBlockHeaderSizeInBytes);
     fStack.push_back({ codeSnippetID, this->sizeInBytes(),
                        SkDEBUGCODE(kHeaderExpectations, 0) });
 
@@ -102,7 +101,7 @@ void SkPaintParamsKeyBuilder::endBlock() {
 
     fData[headerOffset+SkPaintParamsKey::kBlockSizeOffsetInBytes] = blockSize;
 
-    fStack.pop_back();
+    fStack.pop();
 
 #ifdef SK_DEBUG
     if (!fStack.empty()) {
@@ -140,7 +139,7 @@ void SkPaintParamsKeyBuilder::addBytes(uint32_t numBytes, const uint8_t* data) {
 
     SkASSERT(!this->isLocked());
 
-    fData.push_back_n(numBytes, data);
+    fData.append(numBytes, data);
 }
 
 SkPaintParamsKey SkPaintParamsKeyBuilder::lockAsKey() {
@@ -154,17 +153,17 @@ SkPaintParamsKey SkPaintParamsKeyBuilder::lockAsKey() {
     // Partially reset for reuse. Note that the key resulting from this call will be holding a lock
     // on this builder and must be deleted before this builder is fully reset.
     fIsValid = true;
-    fStack.clear();
+    fStack.rewind();
 
-    return SkPaintParamsKey(SkMakeSpan(fData.data(), fData.count()), this);
+    return SkPaintParamsKey(SkMakeSpan(fData.begin(), fData.count()), this);
 }
 
 void SkPaintParamsKeyBuilder::makeInvalid() {
     SkASSERT(fIsValid);
     SkASSERT(!this->isLocked());
 
-    fStack.clear();
-    fData.reset();
+    fStack.rewind();
+    fData.rewind();
     this->beginBlock(SkBuiltInCodeSnippetID::kError);
     this->endBlock();
 
diff --git a/src/core/SkPaintParamsKey.h b/src/core/SkPaintParamsKey.h
index 8f716f7412..f244d70a76 100644
--- a/src/core/SkPaintParamsKey.h
+++ b/src/core/SkPaintParamsKey.h
@@ -10,12 +10,11 @@
 
 #include "include/core/SkSpan.h"
 #include "include/core/SkTypes.h"
-#include "include/private/SkTArray.h"
+#include "include/private/SkTDArray.h"
 #include "src/core/SkBuiltInCodeSnippetID.h"
 
 #include <array>
 #include <limits>
-#include <vector>
 
 enum class SkBackend : uint8_t {
     kGanesh,
@@ -195,7 +194,7 @@ public:
 
     void unlock() {
         SkASSERT(fLocked);
-        fData.reset();
+        fData.rewind();
         SkDEBUGCODE(fLocked = false;)
         SkDEBUGCODE(this->checkReset();)
     }
@@ -215,15 +214,18 @@ private:
 #endif
     };
 
-    bool fIsValid = true;
     const SkShaderCodeDictionary* fDict;
-    const SkBackend fBackend;
-    std::vector<StackFrame> fStack;
-
     // TODO: It is probably overkill but we could encode the SkBackend in the first byte of
     // the key.
+    const SkBackend fBackend;
+
+    bool fIsValid = true;
     SkDEBUGCODE(bool fLocked = false;)
-    SkTArray<uint8_t, true> fData;
+
+    // Use SkTDArray so that we can guarantee that rewind() preserves the underlying storage and
+    // repeated use of the builder will hit a high-water mark and avoid lots of allocations.
+    SkTDArray<StackFrame> fStack;
+    SkTDArray<uint8_t> fData;
 };
 
 #endif // SkPaintParamsKey_DEFINED