Thanks to @Evgeni_Popov i was able to add globalUVs (uv6) for diffuse texture and particle UVs for heatmap texture and blend them together. Here is my current PG.
Adding some screenshots:
With trilinear sampling mode:
Now i am considering sending the data texture as single value only (so only R, G, B or A) to the shader along with some uniform for mapping the texture channel value to color.