Hi, as reported in a thread (https://mods.factorio.com/mod/Ultracube/discussion/65987d4075514d8c7a8b81fc) this mod causes script errors when used in Ultracube because it calls surface.create_entity and entity.destroy on chests without setting raise_built = true and raise_destroy = true respectively. I'm not sure if changing this is something you would consider, but otherwise I had to mark this mod as incompatible for now.
Hi, I think the events for merged chests shouldn't be raised in general because theoretically the entity was not created/destroyed. Do you know if the event is used by the game itself (for example to show the created/destroyed entities in the kill statistic dialog)?
Anyway I'll raise the event if your mod is detected.