diff --git a/.github/workflows/local-testnet.yml b/.github/workflows/local-testnet.yml
index 42293d38a79..9b61921d9ee 100644
--- a/.github/workflows/local-testnet.yml
+++ b/.github/workflows/local-testnet.yml
@@ -39,12 +39,6 @@ jobs:
         run: |
           brew tap ethereum/ethereum
           brew install ethereum
-      - name: Install GNU sed & GNU grep
-        if: matrix.os == 'macos-12'
-        run: |
-          brew install gnu-sed grep
-          echo "$(brew --prefix)/opt/gnu-sed/libexec/gnubin" >> $GITHUB_PATH
-          echo "$(brew --prefix)/opt/grep/libexec/gnubin" >> $GITHUB_PATH
       # https://github.com/actions/cache/blob/main/examples.md#rust---cargo
       - uses: actions/cache@v4
         id: cache-cargo
diff --git a/scripts/local_testnet/README.md b/scripts/local_testnet/README.md
index 77c9d62c1cd..b3a3479a343 100644
--- a/scripts/local_testnet/README.md
+++ b/scripts/local_testnet/README.md
@@ -8,8 +8,6 @@ This setup can be useful for testing and development.
 The scripts require `lcli`, `lighthouse`, `geth`, `bootnode` to be installed on `PATH` (run `echo $PATH` to view all `PATH` directories).
 
 
-MacOS users need to install GNU `sed` and GNU `grep`, and add them both to `PATH` as well.
-
 The first step is to install Rust and dependencies. Refer to the [Lighthouse Book](https://lighthouse-book.sigmaprime.io/installation-source.html#dependencies) for installation. We will also need [jq](https://jqlang.github.io/jq/), which can be installed with `sudo apt install jq`.
 
 Then, we clone the Lighthouse repository:
diff --git a/scripts/local_testnet/bootnode.sh b/scripts/local_testnet/bootnode.sh
index ca02a24140f..7c917045c84 100755
--- a/scripts/local_testnet/bootnode.sh
+++ b/scripts/local_testnet/bootnode.sh
@@ -28,7 +28,9 @@ DEBUG_LEVEL=${1:-info}
 
 echo "Starting bootnode"
 
-exec lighthouse boot_node \
+exec lighthouse \
+    --debug-level $DEBUG_LEVEL \
+    boot_node \
     --testnet-dir $TESTNET_DIR \
     --port $BOOTNODE_PORT \
     --listen-address 127.0.0.1 \
diff --git a/scripts/local_testnet/setup_time.sh b/scripts/local_testnet/setup_time.sh
index 36f7fc4e997..39551b860b8 100755
--- a/scripts/local_testnet/setup_time.sh
+++ b/scripts/local_testnet/setup_time.sh
@@ -20,16 +20,21 @@ echo "slot_per_epoch=$SLOT_PER_EPOCH"
 genesis_file=$1
 
 # Update future hardforks time in the EL genesis file based on the CL genesis time
-GENESIS_TIME=$(lcli pretty-ssz --spec $SPEC_PRESET --testnet-dir $TESTNET_DIR BeaconState $TESTNET_DIR/genesis.ssz | jq | grep -Po 'genesis_time": "\K.*\d')
-echo $GENESIS_TIME
+GENESIS_TIME=$(lcli pretty-ssz --spec $SPEC_PRESET --testnet-dir $TESTNET_DIR BeaconState $TESTNET_DIR/genesis.ssz | jq | sed -n 's/.*genesis_time": "\([0-9]*\).*/\1/p')
+echo "GENESIS_TIME: $GENESIS_TIME"
+
 CAPELLA_TIME=$((GENESIS_TIME + (CAPELLA_FORK_EPOCH * $SLOT_PER_EPOCH * SECONDS_PER_SLOT)))
-echo $CAPELLA_TIME
-sed -i 's/"shanghaiTime".*$/"shanghaiTime": '"$CAPELLA_TIME"',/g' $genesis_file
+echo "SHANGHAI_TIME: $CAPELLA_TIME"
+sed 's/"shanghaiTime".*$/"shanghaiTime": '"$CAPELLA_TIME"',/g' $genesis_file > "/tmp/genesis.json"
+mv "/tmp/genesis.json" $genesis_file
+
 CANCUN_TIME=$((GENESIS_TIME + (DENEB_FORK_EPOCH * $SLOT_PER_EPOCH * SECONDS_PER_SLOT)))
-echo $CANCUN_TIME
-sed -i 's/"cancunTime".*$/"cancunTime": '"$CANCUN_TIME"',/g' $genesis_file
-PRAGUE_TIME=$((GENESIS_TIME + (ELECTRA_FORK_EPOCH * $SLOT_PER_EPOCH * SECONDS_PER_SLOT)))
-echo $PRAGUE_TIME
-sed -i 's/"pragueTime".*$/"pragueTime": '"$PRAGUE_TIME"',/g' $genesis_file
-cat $genesis_file
+echo "CANCUN_TIME: $CANCUN_TIME"
+sed 's/"cancunTime".*$/"cancunTime": '"$CANCUN_TIME"',/g' $genesis_file > "/tmp/genesis.json"
+mv "/tmp/genesis.json" $genesis_file
 
+
+PRAGUE_TIME=$((GENESIS_TIME + (ELECTRA_FORK_EPOCH * $SLOT_PER_EPOCH * SECONDS_PER_SLOT)))
+echo "PRAGUE_TIME: $PRAGUE_TIME"
+sed 's/"pragueTime".*$/"pragueTime": '"$PRAGUE_TIME"',/g' $genesis_file > "/tmp/genesis.json"
+mv "/tmp/genesis.json" $genesis_file
diff --git a/scripts/local_testnet/start_local_testnet.sh b/scripts/local_testnet/start_local_testnet.sh
index 77422095130..b2c3b193cef 100755
--- a/scripts/local_testnet/start_local_testnet.sh
+++ b/scripts/local_testnet/start_local_testnet.sh
@@ -132,9 +132,14 @@ done
 sleeping 20
 
 # Reset the `genesis.json` config file fork times.
-sed -i 's/"shanghaiTime".*$/"shanghaiTime": 0,/g' $genesis_file
-sed -i 's/"cancunTime".*$/"cancunTime": 0,/g' $genesis_file
-sed -i 's/"pragueTime".*$/"pragueTime": 0,/g' $genesis_file
+sed 's/"shanghaiTime".*$/"shanghaiTime": 0,/g' $genesis_file > "/tmp/genesis.json"
+mv "/tmp/genesis.json" $genesis_file
+
+sed 's/"cancunTime".*$/"cancunTime": 0,/g' $genesis_file > "/tmp/genesis.json"
+mv "/tmp/genesis.json" $genesis_file
+
+sed 's/"pragueTime".*$/"pragueTime": 0,/g' $genesis_file > "/tmp/genesis.json"
+mv "/tmp/genesis.json" $genesis_file
 
 for (( bn=1; bn<=$BN_COUNT; bn++ )); do
     secret=$DATADIR/geth_datadir$bn/geth/jwtsecret