The flamethrower lemurian throws quite a long error if MCA is installed (relevant code for MCA here, it's basically just a CalculateFinalRechargeInterval hook)
The initial error is this -
[Error : Unity Log] NullReferenceException: Object reference not set to an instance of an object
Stack trace:
RoR2.GenericSkill.get_baseRechargeInterval () (at <abee4f3b46184662b4d0bd0bc9965114>:IL_0006)
and then it just goes on, and on, and on (full log here)