Hello there! Would this work better as a custom step template? You could include a package reference and when a release is created, you can choose which version of the package the use.
Unfortunately, we do not have the ability to have multiple steps within a single step template. What you could do is base your step template off of Run An AWS CLI Script. Using the AWS CLI, you could then upload the referenced package to S3 and perform the remaining steps.
The issue that you’re running into is that the package version is specified when the release is created, so the Chain Deployment and Deploy a Release steps may not work. Our Octopus CLI contains a command to create a release (https://octopus.com/docs/octopus-rest-api/octopus-cli/create-release) which you can specify the package version that way.
The last idea I have is to create the release in the other project by using the API. Like the CLI command, you can specify the package version in the payload.