I looked at this two years ago, and it didn't have TLS 1.3 support, so I went with openssl and have replaced that with s2n (which uses bits of openssl under-the-hood) last year for some things.
The features page looks like TLS 1.3 still isn't supported, and the git changelog doesn't show much happening...
I've hit the 2147483647 limit of indices occasionally in VFX/Graphics with large datasets: memory efficiency was also important, so 32-bit was a necessity (random access is required, so can't dynamically pack), so I tend to use unsigned these days (uint32_t) within arrays, but native 64-bit lengths (normally size_t) as standard local variables, and I normally go with unsigned there as well.
Several APIs in the VFX arena (Pixar OpenSubD, Pixar USD, and Foundry's Katana GeoLib API) all use signed ints for indices which I've occasionally argued against, with the response being "Google's coding standard says don't use them".
I looked at this two years ago, and it didn't have TLS 1.3 support, so I went with openssl and have replaced that with s2n (which uses bits of openssl under-the-hood) last year for some things.
The features page looks like TLS 1.3 still isn't supported, and the git changelog doesn't show much happening...