Premiere Pro M1 Beta Export is not faster than Rosetta 2 Intel Premiere Pro 14.7?

I exported the same video using the intel version of Premiere Pro 14.7 and Premiere Pro Beta on my M1 Macbook Air (8GB), but their exporting time was the same. I thought the beta version would perform better. Is this as expected? Project information below.

- Input: 4K MP4 8:52 video (4GB)

- Effect: Lens Distortion

- Export Format: H.264

- Export Preset: Youtube 2160p 4K Ultra HD

- Encoding Performance: Hardware Encoding

Export time

- Beta: 5:36

- Rosetta 2: 5:41