diff --git a/jjb/pipeline/voltha-scale-test.groovy b/jjb/pipeline/voltha-scale-test.groovy
index d716441..a5dd815 100644
--- a/jjb/pipeline/voltha-scale-test.groovy
+++ b/jjb/pipeline/voltha-scale-test.groovy
@@ -175,31 +175,42 @@
 
             export EXTRA_HELM_FLAGS+=' '
 
-            if [ '${release}' -ne 'master' ]; then
+            # Load the release defaults
+            if [ '${release.trim()}' != 'master' ]; then
               source $WORKSPACE/kind-voltha/releases/${release}
             fi
 
             # BBSim custom image handling
-            IFS=: read -r bbsimRepo bbsimTag <<< ${bbsimImg}
-            EXTRA_HELM_FLAGS+="--set images.bbsim.repository=\$bbsimRepo,images.bbsim.tag=\$bbsimTag "
+            if [ '${bbsimImg.trim()}' != '' ]; then
+              IFS=: read -r bbsimRepo bbsimTag <<< '${bbsimImg.trim()}'
+              EXTRA_HELM_FLAGS+="--set images.bbsim.repository=\$bbsimRepo,images.bbsim.tag=\$bbsimTag "
+            fi
 
             # VOLTHA and ofAgent custom image handling
-            IFS=: read -r rwCoreRepo rwCoreTag <<< ${rwCoreImg}
-            IFS=: read -r ofAgentRepo ofAgentTag <<< ${ofAgentImg}
-            EXTRA_HELM_FLAGS+="--set images.rw_core.repository=\$rwCoreRepo,images.rw_core.tag=\$rwCoreTag,images.ofagent.repository=\$ofAgentRepo,images.ofagent.tag=\$ofAgentTag "
+            # NOTE to override the rw-core image in a released version you must set the ofAgent image too
+            if [ '${rwCoreImg.trim()}' != '' ] && [ '${ofAgentImg.trim()}' != '' ]; then
+              IFS=: read -r rwCoreRepo rwCoreTag <<< '${rwCoreImg.trim()}'
+              IFS=: read -r ofAgentRepo ofAgentTag <<< '${ofAgentImg.trim()}'
+              EXTRA_HELM_FLAGS+="--set images.rw_core.repository=\$rwCoreRepo,images.rw_core.tag=\$rwCoreTag,images.ofagent.repository=\$ofAgentRepo,images.ofagent.tag=\$ofAgentTag "
+            fi
 
             # OpenOLT custom image handling
-            IFS=: read -r openoltAdapterRepo openoltAdapterTag <<< ${openoltAdapterImg}
-            EXTRA_HELM_FLAGS+="--set images.adapter_open_olt.repository=\$openoltAdapterRepo,images.adapter_open_olt.tag=\$openoltAdapterTag "
+            if [ '${openoltAdapterImg.trim()}' != '' ]; then
+              IFS=: read -r openoltAdapterRepo openoltAdapterTag <<< '${openoltAdapterImg.trim()}'
+              EXTRA_HELM_FLAGS+="--set images.adapter_open_olt.repository=\$openoltAdapterRepo,images.adapter_open_olt.tag=\$openoltAdapterTag "
+            fi
 
             # OpenONU custom image handling
-            IFS=: read -r openonuAdapterRepo openonuAdapterTag <<< ${openonuAdapterImg}
-            EXTRA_HELM_FLAGS+="--set images.adapter_open_onu.repository=\$openonuAdapterRepo,images.adapter_open_onu.tag=\$openonuAdapterTag "
+            if [ '${openonuAdapterImg.trim()}' != '' ]; then
+              IFS=: read -r openonuAdapterRepo openonuAdapterTag <<< '${openonuAdapterImg.trim()}'
+              EXTRA_HELM_FLAGS+="--set images.adapter_open_onu.repository=\$openonuAdapterRepo,images.adapter_open_onu.tag=\$openonuAdapterTag "
+            fi
 
             # ONOS custom image handling
-            IFS=: read -r onosRepo onosTag <<< ${onosImg}
-            EXTRA_HELM_FLAGS+="--set images.onos.repository=\$onosRepo,images.onos.tag=\$onosTag "
-
+            if [ '${onosImg.trim()}' != '' ]; then
+              IFS=: read -r onosRepo onosTag <<< '${onosImg.trim()}'
+              EXTRA_HELM_FLAGS+="--set images.onos.repository=\$onosRepo,images.onos.tag=\$onosTag "
+            fi
 
             # set BBSim parameters
             EXTRA_HELM_FLAGS+='--set enablePerf=true,pon=${pons},onu=${onus} '
diff --git a/jjb/voltha-scale.yaml b/jjb/voltha-scale.yaml
index f0e9ae2..4655837 100644
--- a/jjb/voltha-scale.yaml
+++ b/jjb/voltha-scale.yaml
@@ -243,7 +243,12 @@
           release: voltha-2.4
           karafHome: apache-karaf-4.2.8
           logLevel: INFO
+          bbsimImg: ''
+          rwCoreImg: ''
+          ofAgentImg: ''
           openoltAdapterImg: matteoscandolo/voltha-openolt-adapter:per-gem-lock
+          openonuAdapterImg: ''
+          onosImg: ''
 
       - 'voltha-scale-measurements':
           name: 'voltha-scale-measurements-voltha-2.4-2-16-32-dt-subscribers'
@@ -265,7 +270,12 @@
           release: voltha-2.4
           karafHome: apache-karaf-4.2.8
           logLevel: INFO
+          bbsimImg: ''
+          rwCoreImg: ''
+          ofAgentImg: ''
           openoltAdapterImg: matteoscandolo/voltha-openolt-adapter:per-gem-lock
+          openonuAdapterImg: ''
+          onosImg: ''
 
       # development pipeline
       - 'voltha-scale-measurements-dev':