OH! Sorry about the delay, I thought I checked the forums over the weekend and didn't see any new posts.
Since you already went over the rules I've added both kdoyon and luschd to our whitelist. You should be able to connect now, using mc.indiesquish.com
Our main world is currently back in 1.10, as we had fired off a 'doom event' when the update aquatic hit, but we're still waiting on the plugins we use for admin tasks. As soon as they are updated, we'll be updating the entire server to 1.13. Sorry for any inconvenience.
-Indiesquish admin team