“splunk” is a very broad term. I know folks (some at splunk even) that feed osquery into splunk. osquery is an agent. It presents a unified sql-like interface to various other APIs. If you like that idea, you can use it to push logs where ever you like. Splunk, syslog, ELK, AWS, etc. I not familiar with a powershell based endpoint agent. Kinda up to you — Would you rather write your queries in powershell or osquery? Folks here are going to be more familiar with osquery