FloatVectorOperations::copy uses memcpy, so if my source and destination overlap it is not safe, am I right ?
if so, would you consider adding FloatVectorOperations::move calling memmove ?

Yes, I could do, though TBH that's not a common operation in audio buffers, where you're typically streaming from one buffer to another rather than shifting data around inside a buffer. And TBH it's probably just as fast to call std::memmove, which will do a fairly optimal job on most platforms.