[janwas]

Highway TL here. I agree with the main points, with a few clarifications:

> tag-dispatched free functions like hn::Mul(d, a, b)

We only require tags for certain ops, mainly memory, casts and reduction; not arithmetic. Operator overloading is supported but until recently compilers didn't allow that for SVE vectors.

> It’s a Google project with Google-scale maintenance, but the bus factor is real — the core development is driven by a small team

We have 101 contributors, including 14 current or former Googlers in several teams.

> being length-agnostic means you can’t easily express fixed-width algorithms that depend on knowing the vector size at compile time, which is common in cryptography and codec work

We explicitly support fixed-length 128-bit vectors, acknowledging that these are common and important.