I am not Mac aware, I would suggest turning off any programs running in the background, dissabling any power budget schemes. Usually due to programs competing for system resources.

Try a different keyboard and mouse. I've seen more than one instance of them causing mayhem.

Nicest Guy on the forum.

I'm in the process of repacking some Hi8 and HDV legacy items myself.

You may wish to double check whatever power management utilities the laptop may use. Some may be in system BIOS.

The LG consumer OLEDS yield nice images, I find you have to turn off all the factory enabled picture "enhancements" in advanced settings, lower the contrast and chroma levels, then you get a very "honest" display.

Hi Pat, I had to smile. Sort of like Dad talking his son out of a Corvette into a Camry...

Most advise can be offered on established hardware with some track record. whilst new and latest is more, "no reason why it should not work".

Have you tried Apple diagnostics? Possibly a flaw in system memory.

If you are encoding to AVC rather than mpeg-2 that time seems right on a PC of that capability.