Hello! Me again with more seeds I found and checked (on bedrock but could be right on Java too!)

For the 22062004 one, you’ll have to look for a minute or two. There is multiple caves and good places to build, easy to find in spectator mode
For the last one, make sure you follow the coordinates or you won’t find it (I forgot there were ones at first)
For the twin islands, you spawn on the right one in a cove like place, very pretty and the one you spawn on is bigger than it look+ there is a tiny one next to it