I see you’ve makered this as solved, but is it really? I’m having trouble with getting Pass-By-Refrences to work in Custom Events too (in both UE 4.27 and 5.2). Just doesn’t seem to work. It works with Functions and Macros though.
In a Custom Event, when I check the Pass-By-Ref box, it doesn’t turn into a diamond shape pin. The only way to get that pin is to drag off the Target on the Set Float By-Ref node, but then I get the warning as seen in Timophobic’s post above and it does not work.
Any ideas welcome. I need this to work with Custom Events as I need to use a Timeline and you can’t use Timelines in Functions or Macros. Thanks