AWS does have a couple of annoying un-configurable limitations:

* There is a Global Accelerator idle timeout of 340 seconds for TCP connections

* And a Global Accelerator idle timeout of 30 seconds for UDP flows.

These timeouts are not customer or support-configurable.

Many customers have requested configurable Global Accelerator timeouts and AWS at least has a feature request open for it, but we have no way of knowing how or if they're prioritizing that.