The original mod doesn't have any examples that actually work with this right now, meaning custom configs. It has some snippets but none of them are full strings that can be placed or modified, to understand how to make them.

{"maze 4 (bifurcation)", "Maze4(8, 40)"}
results in error about "tp"

TP({"maze 4 (bifurcation)", "Maze4(8, 40)"},{"maze 4 (bifurcation)", "Maze4(8, 40)"})
results in error about "create"

By original desctiption:
This one should generate exactly the same as vanilla Factorio water.
{"factorio default", "HF{pattern = Elevation(), heights = {DeepWater(), -3, Water(), 0, Land()}}"}
results in error about "tp"

Are you using the whole string? - like {"maze 4 (bifurcation)", "Maze4(8, 40)"}?

From what I recall, you should just use:

Maze4(8, 40)

like that on the custom string. Nothing more.

They were whole strings yes. I went with Ribbon Maze mod for the playthrough though. It's making ores at deadends while also being more traversable. I could see that with full random world maze there can be chunks you can't get to unless going around extremely long ways. Maybe it's about having more connections in algorithm, but i don't think there was parameter for extra connections.