> I want to remove the object from memory even if it is still referenced in memory  
That makes no sense and it is not possible, it would invalidate every other variable or object property that references it.
But why do you want to do this?

 Set x="Purple,Black,Yellow,Pink,Yellow,White,White,a,b,c,d,e,f"
Set y="Red,Green,Orange,Yellow,z,y,x,w,v"
Set Found=0
For i=1:1:$Length(x,",") {
  For i2=1:1:$Length(y,",") {
    If $Piece(x,",",i)=$Piece(y,",",i2) {
      Write $Piece(x,",",i)," = ",$Piece(y,",",i2),!
      Set Found=i_","_i2
      Return Found
     }
  }
}

It is a custom build Git Studio plugin plus application and CLI, that can handle multiple repositories per namespace. It is one of the reasons I still use Studio.

In the Git plugin, a  %Studio.SourceControl.Base subclass , I get the active branch
Set Active=##class(Git.Utils).GetActiveBranch(Repos.Directory)
If Active["fatal" {
Set sc=##class(Git.Utils).AddToSaveList(Repos.Name)
}
If that gets a fatal I call:
Set Command="cd "_Repository.Directory_" && git config --global --add safe.directory "_Dir
Set sc=..CPipe(Command,.Output)

This process runs under the Studio account

User S-1-5-18 is (Local) Sytem a hidden account, https://learn.microsoft.com/en-us/windows-server/identity/ad-ds/manage/u....
Your IRIS server is probably running under the System account.
I'm using a Git plugin for Studio and let that background process execute the ' git config --global --add safe.directory' command.

That's because the Portal is a ZEN application. CSS is 'hidden' in XData blocks inside the ZEN classes such as %CSP.Portal.Home

XData CSS3Style
{
<style type="text/css"> #selector {
overflow: auto;
}

It just what you define a 'success', from a pure HTTP standpoint *any* HTTP status code is a success, the server was able to return a status code.
If you want to check if a resource exists or not, a 404 is a perfectly successful response.