@droftarts, yes, exactly. I couldn't even get the strands in a ferrule that would fit.
Originally, I tried just reducing the conductor count but that caused the wires to get hot to the touch and the toolboard's mcu was over 100deg C.
So I ended up making a step-down connector that reduces the diameter. basically additional high temp heater cord spliced in and fit in the ferrule.
It's working better now. The MCU is only 64 deg and nothing is hot to the touch.