There is a step already named 'Run a Script'. In that step you can select the options 'Octopus Server' and 'Script file inside a package'. Currently you can only run 1 script inside this temp directory. It would be nice if you could run multiple scripts that are within that package that was extracted to temp directory. This would be useful with SqlPackage.ps1 and SqlCmd.ps1 scripts that run against a DACPAC file inside that Package for example. I think this feature would be useful for other developers purposes as well. Another option is to improve the step 'Deploy a package' so that it can select the option run on 'Octopus Server', then you could just call those scripts inside 'Custom deployment scripts' option when selected.