Do not question the increased risk, only its degree.
700 is not a particularly large number in a community of this size. If first cousin marriage were as harmful as some claim, it would be more in the range of 70,000 damaged children.
BTW, "increased risk" is often a way of obfuscating rather than enlightening the issue. Is that increase 10%, 100% or 1000%? Inquiring minds want to know.
It says “10 times more likely than ...” Is that a risk you or your family would want to take? I don’t want to get in an argument with you because you know so much about it however, they are basically breeding more damaged children than other population groups and in socialist UK, that is a societal cost everyone pays.