PowerShell nested property iteration - powershell

Question

Looking for some input on the scripts below. Essentially I'm retrieving some json data with Invoke-WebRequest. I needed to export many of the properties to CSV. The data returned from Invoke-WebRequest is contained in an array: $devicedetails. This script works for outputting to CSV.
& {
Foreach ($PC in $DeviceDetails)
{
Foreach ($AppName in $PC.categories)
{
ForEach ($App in $AppName.apps)
{
ForEach($Status in $App.health_status)
{
[pscustomobject] #{
"Device ID" = $PC.device_id
"Device Type" = $PC.device_type
"Device Name" = $PC.device_name
Nickname = $PC.nick_name
Last_Seen = $PC.last_seen
Compliance_Category_Status = $Appname.issue
Compliance_Category = $Appname.category_id
Product_Name = $App.name
Product_Vendor = $App.vendor
Product_Version = $App.version
Product_Health_Item = $Status.status
Product_Health_Status = $Status.issue
}
}
}
}
}
} | Export-CSV -PAth $Outfile -NoTypeInformation
Curious if this is the best way to output properties to CSV. Additionally, I now have the need to do some additional processes on the custom object I'm creating but if I assign a variable to that custom object as shown below, it takes several minutes to complete whereas just exporting to CSV takes 12-13 seconds. Why is the performance so bad?
$DeviceOutput= #()
Foreach ($PC in $DeviceDetails)
{
Foreach ($AppName in $PC.categories)
{
ForEach ($App in $AppName.apps)
{
ForEach($Status in $App.health_status)
{
$DeviceOutput += [pscustomobject] #{
"Device ID" = $PC.device_id
"Device Type" = $PC.device_type
"Device Name" = $PC.device_name
"Nickname" = $PC.nick_name
Compliance_Category_Status = $Appname.issue
Compliance_Category = $Appname.category_id
Product_Name = $App.name
Product_Vendor = $App.vendor
Product_Version = $App.version
Product_Health_Item = $Status.status
Product_Health_Status = $Status.issue
}
}
}
}
}