Rogue Amoeba has the details on their website:

Perhaps the single most notable change, however, is something making a return from years back: scripting support. In the years since Audio Hijack Pro 2 was replaced by Audio Hijack 3, we’ve never stopped getting requests for some type of scripting to make a return. After much research and experimentation, we’ll soon be providing a from-the-ground-up JavaScript-based scripting system, as well as Shortcuts support.

I agree with Jason Snell. Audio Hijack has been my go-to audio recording tool for years. As a podcaster, I can record my mic, the Zoom audio, and a combined version of everything all at once. It’s this ability in Audio Hijack that has all of us nerds with our knickers in a bunch about podcasting on the iPad. It’s powerful enough, but it cannot do that.

That said, every time I record a show, I issue a silent prayer for Audio Hijack to get scripting support so I don’t have to take so many manual steps, even using my beloved, there is only so much I can do. This is going to be an awesome update. I can’t wait to put it in the rotation.