Doing "available domain" requests for an SECockpit search is very costly in terms of resources - eg. we need to get through 800 keywords within a few minutes - that's up to 4 times that amount in the form of "available domain" requests:
com (keyword without dashes)
c-o-m (keyword with dashes)
net (keyword without dashes)
n-e-t (keyword with dashes)
However, when you click on a domain extension link in SECockpit, all available domain extensions show up for that specific keyword.