From what I’ve been able to read, people who bought the v1 aren’t looking to get a v3 usually.
I haven’t really looked at all the specs, because should I get one, it’ll be the current iteration anyway. However, iteration is usually made because it’s worth it. So my guess is, if the differences between the 2 are important to you, then just get the v3.
it may still show Librem 13 v2 even if you have v3. That might depend on what you have on it, but I received my Librem v3 in April. I have updated everything but coreboot.
I recently updated coreboot and that seemed to syncrhonize the version numbers. So, where it showed v2 using the dmidecode command, I now see v3. v3 matches the bottom.