Controll Harmony hub device

It is possible, but not through the official integration.

Instead, you have to have an additional device to act as a “man in the middle” server and use custom code developed by a community member.

So it requires strong technical knowledge, but it can be done.

Ask further questions in the following thread:

[RELEASE] KuKuHarmony - DTH and SmartApp that support to control devices in Logitech Harmony(using Harmony-API)