There’s a lot of things to digest in 2019r2
One of the handy things that was added is a new Attribute you can make use of in your own custom controls – DefaultEvent
By adding this attribute to your custom class’ attributes you can make it so any one of the events your custom controls exposes is the “default event”. This is the one that will be selected when a user puts an instance of your control on a layout and adds events to it.
Handy stuff.