The AbyssalCraft, Botania, RandomThings, Tinker's Construct, Natura and Betweenlands grasses still don't support fireflies. :(

The firefly effect is tied to specific grasses/plants and is not generalized. Also, fireflies are limited to biomes that have some level of humidity and isn't too hot. For example, desert/arid biomes/hot will not have the firefly effect.

AbyssalCraft - I elected not to add firefly effects to that grass. The AbyssalCraft biomes in Overworld have an end particle effect and it would seem to be a bit much.

Botania - flowers already have a shimmering/spark particle effect. Not aware of any other grass.

Tinkers slime grass - to me it didn't right to have firefly particles.

Natura - don't see grass as part of the mod. It does have shrooms and crops - I avoid tying fireflies to those.

Betweenlands - not there yet. I been looking at that mod and it's on my list to provide support.

This being said I am looking at increasing the frequency of fireflies from Vanilla items. Just need to figure out a good way to balance it against having BoP installed.

So why not give the choice in the config for adding manually the grass for supporting fireflies ?

You can do that already using external configuration files.

Okay thanks, I will look at it. ;)

Try this condition string: "weather.isNotRaining && isNight && !biome.isDry && ONEOF(biome.temperature,'mild','warm')"

And the chance is low. Essentially it says 1 in 10. Try something like 30-40.

I'm increasing the spawn rate of fireflies for the Vanilla red, yellow, and double tall plants. Should be about 40% more frequent.

Oh I don't think it's the good place for asking about that, but I tried to add my own config for supporting other grass for fireflies you won't support. But the condition doesn't work, I get fireflies all the time :(
https://pastebin.com/jnakNHj4

Anyway I still think you give a support for all the grasses I put in my own external config. ;)

Oh wait it works now, I made made an error in the condition, I had written "isNotRaining" instead of "weather.isNotRainning". And 30 or 40 is too much, I get really more fireflies than with other grasses you already support.

Oh wait the chance is reversed, more the value is high, less there are fireflies.

Yep

It's not really normal. ^^'

Posted a BETA to CurseForge that increases the number of fireflies around Minecraft flowers. Regular Minecraft "tallgrass" does not have this block effect. Other modded plants will be handled via mod support.