Using A Datapack To Change Spawning Rules For Another Mods Blocks

I've heard a great deal about using Datapacks to "configure" other mods, but haven't found much in the way of specifics about how that's done.
What I'd like to do, for example, is change where Botania's Mystical Plants spawn.  Right now their spawn rules are very generic, I'd like to alter that so that they're more biome specific.
My understanding is that this:
{
  "feature": "botania:mystical_flowers",
  "placement": [
    {
      "type": "minecraft:count",
      "count": 2
    },
    {
      "type": "minecraft:rarity_filter",
      "chance": 16
    },
    {
      "type": "minecraft:in_square"
    },
    {
      "type": "minecraft:heightmap",
      "heightmap": "MOTION_BLOCKING_NO_LEAVES"
    },
    {
      "type": "minecraft:biome"
    }
  ]
}