>SMR is also only used in fairly high capacity drives. A 1/2/4 TB drive wouldn't be SMR.

I thought so too, until I bought a 2TB and discovered it's SMR. It turns out there are quite a few 4TB SMRs, and also 2TB and even 1TB SMRs. e.g.

https://www.truenas.com/community/resources/list-of-known-sm...