Which EP(s) should I get

If you remove or set all the houseboats to no visitors allowed, then lagging will be gone. I already saved Isla this way, and always use this saved file. If you want to live on houseboat, then only active household should be fine because the reason of the lag is coming from route failure of inactive households live in the houseboats, include Medina household in land. Some of the houses in land also has route failure. I fixed this myself, then almost no lagging in my game. And you can enjoy wind surfing, water ski..etc.. It's so funny even without resort managing. I like to work as a lifesaver in Isla paradiso.