if (width === 1 || (width !== 4 && arrayBytes.length < 0xFF && val.array.length < 0xFF)) {
    if (!width) bufb.appendUInt8(0xE0);
    length = arrayBytes.length + 1;
    if (typeof val.elementType === 'number') length += 1;
    bufb.appendUInt8(length); // buffer + count + constructor