PS-Connector Version 9.1 -Why does #Phase 2 uses single calls instead of bulk ?

I have PS Connector to sync departments, There is an auto generated step phase2 to resolve the conflicts in the mapping order. And Phase2 is trying to map the Parent ID with the UID_ParentDepartment 
I see it  goes for single call even though parent id is present in bulk department invoke 

<CustomCommand Name="Get-TargetSystemDepartments">
<![CDATA[
$DepsURI ='{0}departments' -f $global:BaseURI
$myResponse = Invoke-RestMethod -Uri $DepsURI -Method GET -Header $global:requestHeader
# Write-Log -Message ("Result: {0}" -f $myResponse.results.count);
# Write-Log -Message ($myResponse | ConvertTo-Json);

foreach ($Department in $myResponse.results) {
# Put object to result set
Add-Member -InputObject $Department -NotePropertyName "ManagerId" -NotePropertyValue ($Department.Manager.businessId);
Add-Member -InputObject $Department -NotePropertyName "CompanyId" -NotePropertyValue ($Department.Company.businessId);
Add-Member -InputObject $Department -NotePropertyName "ParentId" -NotePropertyValue ($Department.Parent.businessId);
}

Return $myResponse.results;
]]>
</CustomCommand>

<CustomCommand Name="Get-TargetSystemDepartment">
<![CDATA[
param(
[parameter(Mandatory=$true,ValueFromPipelineByPropertyName=$true)]
[ValidateNotNullOrEmpty()]
[String]$businessId
);

# Write-Log -Message ("Get-Department: {0}" -f $businessId);
$DepURI ='{0}departments/{1}' -f $global:BaseURI,$businessId
$myResult = Invoke-RestMethod -Uri $DepURI -Method Get -Header $global:requestHeader

# Enrich object

Add-Member -InputObject $myResult.results -NotePropertyName "ManagerId" -NotePropertyValue ($myResult.results.Manager.businessId);
Add-Member -InputObject $myResult.results -NotePropertyName "CompanyId" -NotePropertyValue ($myResult.results.Company.businessId);
# Add-Member -InputObject $myResult.results -NotePropertyName "DeputyId" -NotePropertyValue ($myResult.results.Deputy.businessId);
Add-Member -InputObject $myResult.results -NotePropertyName "ParentId" -NotePropertyValue ($myResult.results.Parent.businessId);
Return $myResult.results;

]]>
</CustomCommand>

______________

<Schema>
<Class Name="Department">
<Properties>
<Property Name="businessId" DataType="String" IsMandatory="true" IsUniqueKey="true">
<ReturnBindings>
<Bind CommandResultOf="Get-TargetSystemDepartments" Path="businessId" />
<Bind CommandResultOf="Get-TargetSystemDepartment" Path="businessId" />
</ReturnBindings>
<CommandMappings>
<Map ToCommand="Get-TargetSystemDepartment" Parameter="businessId" />
</CommandMappings>
</Property>

<Property Name="name" DataType="String" IsDisplay="true" IsMandatory="false">
<ReturnBindings>
<Bind CommandResultOf="Get-TargetSystemDepartments" Path="name" />
<Bind CommandResultOf="Get-TargetSystemDepartment" Path="name" />

</ReturnBindings>
</Property>

<Property Name="parentId" DataType="String" IsMandatory="false">

<ReturnBindings>
<Bind CommandResultOf="Get-TargetSystemDepartments" Path="parentId" />
<Bind CommandResultOf="Get-TargetSystemDepartment" Path="parentId" />
</ReturnBindings>
</Property>

</Properties>

<ReadConfiguration>
<ListingCommand Command="Get-TargetSystemDepartments" />
<CommandSequence>
<Item Command="Get-TargetSystemDepartment" Order="1" />
</CommandSequence>
</ReadConfiguration>

<MethodConfiguration>
</MethodConfiguration>
</Class>