4.1.8 - Set-ADTEnvironmentVariable - append/Remove

Hi everyone, first time poster,

I am trying to append value to the environment variable path and also remove the value afterwards.
Trying to use 'Set-ADTEnvironmentVariable -Variable path -Value c:\windows\temp -Target Machine -append'
But unfortunatly it does not recognise append.
=> Set-ADTEnvironmentVariable · PSAppDeployToolkit

Sounds like this might need reporting as a potential bug:

It's a feature of v4.2. Not available yet