Severe performance degradation with color-customizable particles in Bedrock 26.50/26.51

Since Minecraft Bedrock 26.50, several particles that support color customization through Molang variables cause extremely severe performance degradation when spawned repeatedly through Script API.

This issue is not limited to minecraft:glow_particle. The same behavior also occurs with other color-customizable particles such as:

• minecraft:glow_particle

• minecraft:arrow_spell_emitter

• minecraft:evoker_spell

In previous Bedrock versions, the same scripts and similar particle counts did not cause this level of performance degradation.

I tested the following cases:

1. Color-customizable particles spawned with MolangVariableMap color values
   → Severe FPS drop.

2. The same types of particles spawned without MolangVariableMap
   → Performance can become even worse.

3. Replacing these particles with fixed-color particles while keeping a similar spawn count and similar script logic
   → Performance returns to normal or becomes dramatically better.

This strongly suggests that the issue is related to the rendering or processing path used by color-customizable particles, rather than Script API particle spawning in general or simply the number of particles being spawned.

Example Script API usage:

const molang = new MolangVariableMap();
molang.setColorRGB("variable.color", {
    red: 1,
    green: 0.8,
    blue: 0.2
});

dimension.spawnParticle(
    "minecraft:glow_particle",
    location,
    molang
);

Similar severe performance degradation can also be reproduced with other color-customizable particles such as minecraft:arrow_spell_emitter and minecraft:evoker_spell.

By comparison, fixed-color particles spawned with a similar frequency and quantity do not cause the same extreme FPS drop.

Tested on:

• Minecraft Bedrock 26.50 / 26.51

• Script API 2.10.0

• Windows PC

Expected behavior:

Color-customizable particles should perform similarly to previous Bedrock versions and should not cause extreme FPS degradation compared with fixed-color particles at similar spawn counts.

Actual behavior:

Repeatedly spawning color-customizable particles causes severe FPS degradation and can make the game nearly unresponsive, while fixed-color particles under a similar workload remain significantly lighter.

The issue is easy to reproduce by spawning dozens of color-customizable particles every tick and comparing the result with a fixed-color particle using the same spawn pattern and similar particle count.