Possible Issues with Traveling Merchant over-spawning

[ate0ate]

I made a large personal pack so this may be a conflict, hence the "possibly" in the title. I am using Multi-Mob Lib v1.0.5 and the config is definitely freshly generated as I just made the pack yesterday. I wanted to turn down the frequency of the Travelling Merchant and changed both the spawn rate and the additional rarity bias to 20. That isn't a much lower spawn weight, but the additional rarity is increased quite a bit. However seems to have the opposite effect. I don't know if this is somehow linked to biome, but I have an insane amount of Travelling Merchants now spawning in Savannah biomes. Like four or five per chunk lol. I ended up turning the rarity up to 250 and I still see Travelling merchants in the Savannah, but much closer to default spawn amounts. Any thoughts or suggestions or is this possibly a bug?