How can I Multi-thread parallel process IB REST service operations?

Hi. I'm on Ptools 8.59.22 and I'm using Integration Broker REST service operations to GET, POST, UPSERT data with an outside vendor.

This vendor says I could improve my throughput by multi-threading or parallel processing our APIs.

I don't see anywhere in the peoplebooks for peopletools 8.59 that I can do that, although it does say we can use Queues for Asynchronous services... which doesn't apply to me.

Any ideas out there? Maybe it is a new thing on 8.60?

Thanks!