Might be out of the scope of far lands, but this still relates to a famous world gen glitch so reporting it here anyway.
In 1.13 and above, for some strange reason, Mojang added a salt to seeds presumably to prevent caves from repeating infinitely, despite this ending up very ineffective. If you try using the seed 107038380838084 you'll see that caves, mineshafts and underwater ravines all generate infinitely, but ravines and underwater caves generate as if in a normal world. Subtracting one from the seed and using 107038380838083 will get you a world that infinitely loops ravines and underwater caves, but not everything else.
I suggest adding an option to undo this salt, allowing all five different structure types to loop within the 107038380838084 seed again.

closing as the notice on this mod's readme has announced discontinuation for a while now - feel free to reopen in future if work starts again