Hello.
Fluid Plasma (while placed in world, for example, by overheated reactor) very often spawns fire blocks in the fluid itself and and these blocks very rapidly disappear (because fire can't stay on fluid).
Placing and breaking block (and also updating light, produced by fire) causes update for block/chunk (I hope, you knew this). This behavior of plasma causes such huge lags (especially on client side), so anyone can't play in descent range around this fluid.

Please, remove this behavior from fluid plasma.
If you want some cool or realistic effets - look at such fluids like Pyrotheum and Cryotheum (from Thermal Foundation) and its effects.

Thank you for your work!

/*
MC 1.12.2
Forge 2491
NuclearCraft 2.5a
*/

Will probably make plasma act a little more like steam to be a little more realistic - hopefully will be much less laggy :)

Good point - I will instead only have fire spawn in air blocks.