In mapping random seeds with the datapack Mushroom Hills biomes seem to be significantly more common. I'm positive it's beyond just coincidence. I was wondering why the reason might be and how I might be able to change it because it isn't mentioned in anything I've seen.

This is likely due to Tectonic's increased scale of continents and oceans. Will look into how much more common mushroom islands are at some point in the future and see if changes are needed from there.

Good call that was it, seems the issue has been solved! thanks.