Well, this is not actually an issue but, I wanted the smooth generation of Tectonic, but without the mountains going over rivers and cutting the landscape. I tried to lower the "Erosion_Scale" but it affects a lot of other things, it makes biomes larger (even vanish with some of them), no mountains but when they appears, they extend for many chunks...

I simply wanted the smoother terrain, without changing the biomes and height, is that possible?

This isn't really something you can do.