The Flex Alpha I saw the insides of had an Intel low power 660p series 512GB 2280 NVME with a read and write rate of 1800MBs. The power draw on the 660p is listed as .1w whereas the power draw listed on a Samsung 512GB 980 was 4.3w. Clearly the Intel is better suited powerwise to lightweight notebooks giving up performance to do so.
Dropping in a 980 or 980 Pro would double the performance while draining the battery faster.
My gaming computer has a 1200w power supply so 4 or 5 watts per drive is no concern.