I think you should pause Nauvis evolution until the player actually reaches Nauvis. I was puttering around for way to long with Lignumis because I was having fun with the new mechanics and recipes and by the time I reached Nauvis, the evolution there was 30+. I then had to fight for my life because of expansion and medium biters all over the place.

Since Lignumis is inserted before Nauvis, the evolution should work the same way it does for other planets that come after Nauvis and not start until the player lands.

Otherwise, I really enjoy the mod, keep up the good work!