Allow Deadline with Start-CMApplicationDeployment using UpdateSupersedence
When using the PoSh Cmdlet Start-CMApplicationDeployment with Parameter -UpdateSupersedence et to $true the DeadlineDateTime Parameter it ignored if the Application is deployed as Available - I actually states it in a Warning as well.
But with UpdateSupersedence set to true we need the Deadline Parameter again, to not enforce the updates immediately.
Riho K commented
Same with New-CMApplicationDeployment. No way to change UpdateDeadline value using Powershell cmdlet.