As Per the following response - The individual with UiPath who has been maintaining the UiPath.PowerShell module has been busy over the last year, and no ETA on when we’ll see further improvements.
As for a API method you’ll be looking at POST to
Swagger will show more specifics https://<orchestrator>/swagger/index.html#/Releases/Releases_Get
Can also check the online documentation, it may have examples (Will probably want to search for both “Processes” and “Releases”
The following Postman UiPath Connector Guide also exists which provides some API Examples