Even Solasta has issues with single attacks that do two damage types being counted as two separate instances, requiring multiple concentration checks. A player said that a dev commentated and said that it was coded that way and can't be changed "without great effort".
To me, that was an utterly bizarre response. Certainly different damage types should be split for the purposes of properly calculating damage reduction and immunity, but after that, the new total should be put back together and THAT should be used as the actual damage number. I can think of a few ways to code that, depending on how the damage calculation method is called.
