Biskotaki

Hey there, I recently downloaded Thaumcraft 5 and started playing around with taint on flat worlds and villages to see how it can spread. I usually start the infection by throwing many Bottles of Taint on the ground so it can change the biome to Tainted Biome and start infecting nearby blocks. Although this works, I noticed that it stops spreading when it has successfully infected all blocks inside the taint biome. Outside of it, for example on plains biome, blocks remain intact. I would like to know if there is a way I can make the taint spread without any limitations. I also watched some videos on Thaumcraft 4, and it seems that the taint used to spread more aggressively in that version, is there something I am missing? Thank you for your consideration.