[pedigree]

0.7, which is under developement, includes a vbulletin style ip subnet whitelist. Until I release that, your options are limited to turning off IP testing, precreating accounts or modiying functions_vbsfs.php to include a test for hardcoded IP subnets and then bypassing the ip testing code (below)

$result = checkSFSSpam($ip, 'ip');
if ($result !== VBSFS_NO_TEST) {
sfsActions('ip', $ip, $username, $email, $ip, $result);
}