I only want our CMDB to be updated after the entire install has completed, including Application Services installations. I cant find an EBS Event which does this post Application Services deployment - can somebody help me? (It must exist - surely?)
There is no specific EBS event for CMDB update, its Machine Provisioning event to choose https://docs.vmware.com/en/vRealize-Automation/7.0/vrealize-automation-70-extensibility.pdfsd
If you want an EBS subscription after everything completes, you probably want to use lifecycle state name as VMPSMasterWorkflow32.MachineProvisioned with a state phase of POST.
In addition to what the others have said already but take a look at a reply to another post, which shows where I am carrying out certain customizations:
Re: vRA7.2: End to End request flow withing vRA And vRO
Hopefully provides a little more insight.