I just had to update a single instruction on 130 tasks, changing allow superseded to denying them and without any obvious way to do this through the console I accomplished it using a quick powershell script. I guess to do this properly you'd want to perform xml updates however a simple string replacement worked fine for me and I'll add it to my PM toolbag:
$parents = gci "C:\Program Files (x86)\SolarWinds\Patch Manager\Server\scheduled" foreach ($folder in ($parents.fullname)) { ((Get-Content -path "$folder\task.xml" -Raw) -replace 'dontincludesuperseded="False"','dontincludesuperseded="true"') | Set-Content -Path "$folder\task.xml" }