Minecraft 1.16.5
Forge 36.2.2
Dynamic Surroundings 4.0.4.2
Feywild 1.3.1

Note: I have also turned off in the configs the following for added performance: Config>Feywild>client.json5 - Tree Particles: "false" (and yes I tried true as well)

With both DS & Feywild installed (and supporting lib mods, etc.) the FPS drops when in Feywild biomes. Normal FPS on default settings was around 60 and they drop to as low as 20 at times though average around 30-40. This may not seem like much but add in a few other key mods and your FPS isn't that playable anymore in Feywild biomes. I tried with Better Foliage and it behaves similarly to DS in respect to the FPS drops but other mods like Astral Sorcery have no effect. I can state that the leaves are not actual leaf blocks but that's about all I know.

Think this would be the same underlying issue as Dynamic Trees.

Does this issue still acure with the newest version of Feywild?
Cause Im actually using dynamic surroundings in our own modpack now and experience no issues.

I have no further issues with Dynamic Surroundings or Better Foliage. No idea about Dynamic Trees.