I remember in beta reading that they had trouble with Thermal Shock stacking - so the limited how many you can stack?
is this for all effects?
Is it worth say, having 2 multi cannons with Incendiary Rounds?
Incendiary rounds (IRs) can't stack because they do not apply an effect on the target, it means MC rounds can apply thermal damage like lasers. So you can have all MCs with IRs and they should not affect each other.