Adobe suite not taking advantage of Apple M2 Ultra?

I just upgraded to a Mac Studio M2 Ultra, 24‑core CPU, 76‑core GPU, 192GB memory.

I've allocated 168GB to Adobe apps, enabled Multi-Frame Rendering, set large disk caches for Premiere and AE, and am using Mercury GPU Acceleration.

I would expect exports and preview renders to be blazing fast, and while it's definitely faster than my humble Macbook Pro... it's leaving plenty to be desired.

But I noticed that while exporting, the computer remained fully responsive and I could use other apps with ease – even exporting a second video from another app simultaneously without any freezes. So I checked Activity Monitor during a Premiere export and saw that Premiere was only using 123% CPU and 25% GPU,  and aerendercore was only using 318% CPU.

Overall CPU load was:

System: 7.45%
User: 23.64%
Idle: 68.91%

What gives? How can I get the Adobe suite to stop leaving so much horsepower on the table?