I read about treasure islands many times and yesterday visited one of the free islands by Pange Plays? It was very interesting, looked like it had everything a player would need to get an island to level 5. I think it had 6 free islands with all the raw materials, bells, gold nuggets, star fragments, diys etc . Some things looked like it was better to avoid, such as the bridge construction diy and I avoided the section with creatures. In addition to bells, it had Royal Crowns - 20 will get you 6 million bells at Nooks Cranny. The web page constantly listed who was on each island, along with the current dodo code and a map showing where things were located. The only down side was waiting often as players come and go , and we did get booted when someone left silently. We ended up spending over an hour, looking at various things available on several of the free islands. We live in USA and early morning seemed to be a better time, all 6 free as islands have status updates so you know how busy they are when you visit the website. The free islands are impressive, but there is a paid subscription, about $5 a month for artwork and other harder to get items.
I often read about problems after using treasure islands, but the DIY seemed OK, as well as the items we picked up. Overall not much different than visiting any other island with a giveaway. Well, the island looked different, flat with no sea.
Here is the website, but be careful, you visit at your own risk. I can not say it is safe, it seemed OK to me.
Sorry about the late reply. I'm new to Lemmy, and looking for AC/ACNH communities to join, and share with.
I've used TIs (Treasure Islands) from these people, and if you have Amazon Prime, you can also donate a Twitch sub. Prime gives you one a month at no extra fee, but you do need to have Prime. You can get a trial if you want to use the TIs for a month for free.
People leaving silently (via the minus button) is something I think a couple people do intentionally. They will wait until someone joins an island. Sometimes they follow you around, grabbing the stuff you're interested in. Sometimes they just hang back a bit. After you get a bunch of stuff, sometimes when you go to leave, they quietly leave so you lose all progress. Unfortunately the people who run the TIs really don't care all that much. You can report them (you can see who they are and keep tabs on them, so if they request a Dodo code, you can finish up and leave before they get their Dodo code put in) but it won't do much good. I think it's a game to them, like hunting. I bet they figure if fewer people use the TIs, it's fewer load times for those who are willing to deal with the occasional griefer.
Also, helps if you go during non-peak hours. TIs typically run 24/7.
Thanks for the update