if the old ways are still available, the bad guys can use 'em too.. so this new thing is just to get people 'used to' the idea of an anal probe for verification before actually forcing it on everyone.
i have one. but it isn't android, or ios, or 'smart' in any way. it doesn't even text. it's just a telephone that fits in my pocket and connects to the cellular networks. it's all i want. it's all i use. it's all i've needed ever since i got my first one about 25 years ago.
optane modules can be reformatted and used as a regular m2 nvme ssd. i have used one here before, just drop it in and ran mint or whatever installer and let it do its thing. they're kinda slow (relative to recent gen nvme) but high endurance. so to answer your question, it would displace one of your m2 ssd.
if there's an unused sata port, i'd probably go with your other option--sata boot. take care cloning bootable nvme to sata.
Walmart said in an earnings call last week that it would probably put its tariff refunds toward lowering prices, pointing out that its lower-income customers were navigating increased financial distress.
we've been going backwards on fuel efficiency. the little compact i had back in the early 90s got over 40mpg.