diff --git a/certy.ps1 b/certy.ps1
index 6beae28..cd0805f 100644
--- a/certy.ps1
+++ b/certy.ps1
@@ -237,6 +237,7 @@ function Invoke-Replication {
     param(
         [string[]]$Servers,
         [string]$Command,
+        [bool]$UseRemote,
         [scriptblock]$Log
     )
 
@@ -248,13 +249,27 @@ function Invoke-Replication {
     }
 
     foreach ($server in $targets) {
-        $cmd = if ($Command -match "\{server\}") { $Command.Replace("{server}", $server) } else { $Command }
+        $usesToken = $Command -match "\{server\}"
+        $cmd = if ($usesToken) { $Command.Replace("{server}", $server) } else { $Command }
         $cmd = $cmd.Trim()
         if ($cmd -match "^(?i)\s*/repadmin\b") {
             $cmd = $cmd -replace "^(?i)\s*/repadmin\b", "repadmin"
         }
-        if ($server -and $cmd -match "(?i)\brepadmin\b" -and $cmd -match "(?i)\bsyncall\b" -and $cmd -notmatch "\{server\}") {
-            $cmd = $cmd -replace "(?i)\bsyncall\b", "syncall $server"
+        if ($UseRemote -and $cmd -match "(?i)\brepadmin\b" -and $cmd -match "(?i)\bsyncall\b") {
+            $remoteCmd = [regex]::Replace($cmd, "(?i)\\brepadmin\\s+/syncall\\s+\\S+", "repadmin /syncall")
+            & $Log "Replication (remote): $server -> $remoteCmd"
+            try {
+                Invoke-Command -ComputerName $server -ScriptBlock { param($c) & $env:ComSpec /c $c } -ArgumentList $remoteCmd |
+                    ForEach-Object { & $Log $_ }
+            } catch {
+                & $Log "Replication error on $server: $($_.Exception.Message)"
+            }
+            continue
+        }
+        if (-not $usesToken -and $server -and $cmd -match "(?i)\brepadmin\b" -and $cmd -match "(?i)\bsyncall\b") {
+            if ($cmd -notmatch "(?i)\\bsyncall\\s+\\S+") {
+                $cmd = $cmd -replace "(?i)\\bsyncall\\b", "syncall $server"
+            }
         }
         if ([string]::IsNullOrWhiteSpace($cmd)) { continue }
         & $Log "Replication: $cmd"
@@ -597,7 +612,18 @@ $y += 70 + $gap
 Add-Label "Replication command ({server} optional)" $xLabel $y $labelWidth $rowHeight
 $replicationCmdBox = Add-TextBox $xInput $y $inputWidth $rowHeight $false
 $replicationCmdBox.Text = "repadmin /syncall {server} /AdeP"
-$y += $rowHeight + ($gap * 2)
+$y += $rowHeight + $gap
+
+Add-Label "Replication wait (seconds)" $xLabel $y $labelWidth $rowHeight
+$replicationDelayBox = Add-TextBox $xInput $y $inputWidth $rowHeight $false
+$replicationDelayBox.Text = "30"
+$y += $rowHeight + $gap
+
+$replicationRemoteBox = Add-CheckBox "Run repadmin remotely (PowerShell)" $xInput $y $inputWidth $rowHeight
+$replicationRemoteBox.Checked = $true
+$y += $rowHeight + $gap
+
+$y += $gap
 
 Add-SectionHeader "ACME / Output"
 Add-Label "WACS path" $xLabel $y $labelWidth $rowHeight
@@ -705,6 +731,8 @@ function Update-ReplicationUI {
     $replicationFromSelectedBtn.Enabled = $enabled
     $primaryFromSelectedBtn.Enabled = $enabled
     $replicationCmdBox.Enabled = $enabled
+    $replicationDelayBox.Enabled = $enabled
+    $replicationRemoteBox.Enabled = $enabled
     $dnsListBox.Enabled = $enabled
 }
 
@@ -725,6 +753,16 @@ function Update-CertGenerationUI {
     $validationPortBox.Enabled = -not $disabled
 }
 
+function Update-ZoneFromHostInput {
+    $hostList = @(Split-List $hostsBox.Text)
+    if ($hostList.Count -eq 0) { return }
+    $zoneGuess = Get-CommonZoneFromHosts -Hosts $hostList
+    if (-not [string]::IsNullOrWhiteSpace($zoneGuess) -and $zoneBox.Text -ne $zoneGuess) {
+        $zoneBox.Text = $zoneGuess
+        & $logAction "Default DNS zone set to $zoneGuess (from hostnames)."
+    }
+}
+
 $loadedDefaults = Load-Defaults
 if ($loadedDefaults) {
     $value = Get-DefaultValue -Defaults $loadedDefaults -Name "DefaultZone"
@@ -745,6 +783,12 @@ if ($loadedDefaults) {
     $value = Get-DefaultValue -Defaults $loadedDefaults -Name "ReplicationEnabled"
     if ($null -ne $value) { $replicationEnabledBox.Checked = [bool]$value }
 
+    $value = Get-DefaultValue -Defaults $loadedDefaults -Name "ReplicationDelaySeconds"
+    if ($null -ne $value) { $replicationDelayBox.Text = $value.ToString() }
+
+    $value = Get-DefaultValue -Defaults $loadedDefaults -Name "ReplicationRemote"
+    if ($null -ne $value) { $replicationRemoteBox.Checked = [bool]$value }
+
     $value = Get-DefaultValue -Defaults $loadedDefaults -Name "WacsPath"
     if (-not [string]::IsNullOrWhiteSpace($value)) { $wacsPathBox.Text = $value }
 
@@ -817,6 +861,8 @@ function Apply-Layout {
     $replicationFromSelectedBtn.Left = $xInput + $inputWidthCalc - ((2 * $buttonWidth) + $buttonGap)
     $primaryFromSelectedBtn.Left = $xInput + $inputWidthCalc - $buttonWidth
     $replicationCmdBox.Width = $inputWidthCalc
+    $replicationDelayBox.Width = $inputWidthCalc
+    $replicationRemoteBox.Width = $inputWidthCalc
     $wacsPathBox.Width = $inputWidthCalc
     $outputTypeBox.Width = $inputWidthCalc
     $outputPathBox.Width = $inputWidthCalc
@@ -954,6 +1000,10 @@ $outputTypeBox.Add_SelectedIndexChanged({
     Update-OutputTypeUI
 })
 
+$hostsBox.Add_TextChanged({
+    Update-ZoneFromHostInput
+})
+
 $disableCertsBox.Add_CheckedChanged({
     Update-CertGenerationUI
 })
@@ -966,6 +1016,8 @@ $saveDefaultsBtn.Add_Click({
         ReplicationTargets  = $replicationTargetsBox.Text
         ReplicationCommand  = $replicationCmdBox.Text
         ReplicationEnabled  = $replicationEnabledBox.Checked
+        ReplicationDelaySeconds = $replicationDelayBox.Text
+        ReplicationRemote   = $replicationRemoteBox.Checked
         WacsPath            = $wacsPathBox.Text
         OutputType          = $outputTypeBox.SelectedItem.ToString()
         OutputPath          = $outputPathBox.Text
@@ -1034,6 +1086,13 @@ $runBtn.Add_Click({
         }
 
         if ($replicationEnabledBox.Checked) {
+            $replicationDelaySeconds = 0
+            $delayRaw = $replicationDelayBox.Text.Trim()
+            if (-not [string]::IsNullOrWhiteSpace($delayRaw)) {
+                if (-not [int]::TryParse($delayRaw, [ref]$replicationDelaySeconds) -or $replicationDelaySeconds -lt 0) {
+                    throw "Replication wait seconds must be a non-negative integer."
+                }
+            }
             if ($selectedReplicationTargets.Count -gt 0) {
                 $replicationTargets = $selectedReplicationTargets
             } else {
@@ -1043,7 +1102,11 @@ $runBtn.Add_Click({
                     & $logAction "Replication targets empty; using primary DNS server $dnsServer."
                 }
             }
-            Invoke-Replication -Servers $replicationTargets -Command $replicationCmdBox.Text -Log $logAction
+            Invoke-Replication -Servers $replicationTargets -Command $replicationCmdBox.Text -UseRemote $replicationRemoteBox.Checked -Log $logAction
+            if ($replicationDelaySeconds -gt 0) {
+                & $logAction "Waiting $replicationDelaySeconds seconds for replication."
+                Start-Sleep -Seconds $replicationDelaySeconds
+            }
         } else {
             & $logAction "Replication disabled."
         }