diff --git a/wled00/FX_fcn.cpp b/wled00/FX_fcn.cpp
index 08024fa9c..2a3c51de9 100644
--- a/wled00/FX_fcn.cpp
+++ b/wled00/FX_fcn.cpp
@@ -90,18 +90,21 @@ Segment::Segment(const Segment &orig) {
   //DEBUG_PRINTF("-- Copy segment constructor: %p -> %p\n", &orig, this);
   memcpy((void*)this, (void*)&orig, sizeof(Segment));
   _t = nullptr; // copied segment cannot be in transition
-  if (orig.name) { name = new char[strlen(orig.name)+1]; if (name) strcpy(name, orig.name); } else { name = nullptr; }
-  if (orig.data) { if (allocateData(orig._dataLen)) memcpy(data, orig.data, orig._dataLen); } else { data = nullptr; _dataLen = 0; }
+  name = nullptr;
+  data = nullptr;
+  _dataLen = 0;
+  if (orig.name) { name = new char[strlen(orig.name)+1]; if (name) strcpy(name, orig.name); }
+  if (orig.data) { if (allocateData(orig._dataLen)) memcpy(data, orig.data, orig._dataLen); }
 }
 
 // move constructor
 Segment::Segment(Segment &&orig) noexcept {
   //DEBUG_PRINTF("-- Move segment constructor: %p -> %p\n", &orig, this);
   memcpy((void*)this, (void*)&orig, sizeof(Segment));
+  orig._t   = nullptr; // old segment cannot be in transition any more
   orig.name = nullptr;
   orig.data = nullptr;
   orig._dataLen = 0;
-  orig._t   = nullptr; // old segment cannot be in transition any more
 }
 
 // copy assignment
@@ -110,14 +113,7 @@ Segment& Segment::operator= (const Segment &orig) {
   if (this != &orig) {
     // clean destination
     if (name) { delete[] name; name = nullptr; }
-    if (orig.name) { name = new char[strlen(orig.name)+1]; if (name) strcpy(name, orig.name); }
-    if (_t) {
-      #ifndef WLED_DISABLE_MODE_BLEND
-      if (_t->_segT._dataT) free(_t->_segT._dataT);
-      #endif
-      delete _t;
-      _t = nullptr; // copied segment cannot be in transition
-    }
+    stopTransition();
     deallocateData();
     // copy source
     memcpy((void*)this, (void*)&orig, sizeof(Segment));
@@ -125,6 +121,7 @@ Segment& Segment::operator= (const Segment &orig) {
     data = nullptr;
     _dataLen = 0;
     // copy source data
+    if (orig.name) { name = new char[strlen(orig.name)+1]; if (name) strcpy(name, orig.name); }
     if (orig.data) { if (allocateData(orig._dataLen)) memcpy(data, orig.data, orig._dataLen); }
   }
   return *this;
@@ -135,13 +132,7 @@ Segment& Segment::operator= (Segment &&orig) noexcept {
   //DEBUG_PRINTF("-- Moving segment: %p -> %p\n", &orig, this);
   if (this != &orig) {
     if (name) { delete[] name; name = nullptr; } // free old name
-    if (_t) {
-      #ifndef WLED_DISABLE_MODE_BLEND
-      if (_t->_segT._dataT) free(_t->_segT._dataT);
-      #endif
-      delete _t;
-      _t = nullptr;
-    }
+    stopTransition();
     deallocateData(); // free old runtime data
     memcpy((void*)this, (void*)&orig, sizeof(Segment));
     orig.name = nullptr;
@@ -153,10 +144,13 @@ Segment& Segment::operator= (Segment &&orig) noexcept {
 }
 
 bool Segment::allocateData(size_t len) {
-  if (data && _dataLen == len) return true; //already allocated
+  if (data && _dataLen >= len) {          // already allocated enough (reduce fragmentation)
+    if (call == 0) memset(data, 0, len);  // erase buffer if called during effect initialisation
+    return true;
+  }
   //DEBUG_PRINTF("--   Allocating data (%d): %p\n", len, this);
   deallocateData();
-  if (len == 0) return(false); // nothing to do
+  if (len == 0) return false; // nothing to do
   if (Segment::getUsedSegmentData() + len > MAX_SEGMENT_DATA) {
     // not enough memory
     DEBUG_PRINT(F("!!! Effect RAM depleted: "));