What affects the transcoding speed of Zoom recordings the most?

I am shopping for a new Mac computer.

I record 8-hour Zoom sessions every day and I want to publish them to Youtube as fast as possible. So I want the new computer to transcode the Zoom recordings as fast as possible.

At the same time I do not want to needlessly pay for the expensive hardware that Zoom will not take advantage of.

So what affects the encoding time of Zoom recordings the most? I am using "Optimize for 3rd party video editor" setting to further process the recordings with Timebolt, if that affects anything.

Is it the CPU core count?

Is it the GPU core count?

Is it the amount of Unified Memory (RAM)?

Is it the speed of Unified Memory (200 vs 400 GB/s)?

Is it the presence of media encoder in M1 Pro/Max/M2?

What would be the recommended Macbook specs for maximizing Zoom transcoding times while keeping the cost of the computer under control?