OptionalallowSend parameter keys that are not in the endpoint's list (FIND_PARAM_KEYS, …),
for a parameter GENESIS added after the list was written. Default false: an
unknown key is rejected, because GENESIS ignores it and answers unfiltered. The
value must still be a string, number or boolean, and __proto__, constructor
and prototype are never accepted.
Options for a client call that takes a parameter object.