Hey mgumley-
PrimaryComponentTick.bCanEverTick appears to be working in the component constructor for me. When set to false, the “Is Component Tick Enabled” node will correctly return false when called from a blueprint using my custom component. To enable ticking for the component, first bCanEverTick needs to be set to true, then SetComponentTickEnabled(true) needs to be called. SetComponentTickEnabled() will check if bCanEverTick is true and, if so, will call SetTickFunctionEnabled(). This is why you have to update bCanEverTick prior to calling SetComponentTickEnabled().
Cheers