Thank you so much, @Deltakosh for fixing/incorporating the blendMode property for the SpriteManager! I just this morning finally went to make the changes you suggested, and saw that you had already done it!
However, the blend modes do not behave as expected, unfortunately. I guess that may mean removing the feature before 4.1, but if we can make it work, it would be incredible.
Here is the look we had achieved before using particles and a little circular fire sprite:
The look we had with particles
We were using the ONEONE mode to add the particles over one another and the terrain below, so that the fire gets brighter where the particles were denser. When they are animated, the result is very pleasing. We moved to sprites because they solved performance problems, but as you can see in the playground below, the sprites block one another despite the blend mode.
Let me know if I can be of any help.