Is your UKG instance hosted in your internal network, or is it an external SaaS solution? If it’s internal, then your only option at this time is the Web Services connector since it runs on the VA and can access internal resources.
If your UKG instance is external, I recommend using SaaS Connectivity to implement the connector, which offers greater control and better development features when integrating with web service sources.
As for the data not reflecting immediately, that would depend on two things.
how often are you aggregating your UKG source in IDN? This can be controlled from the Account Aggregation page in your source configuration.
How long it takes UKG to make data available via its API. I’m not familiar with UKG, so I don’t know if data if available immediately, or if there is a latency for when it is stored in the database and made available to the API. That would be a question for UKG.