Perspective - Breakpoint - Get view size

Hello folks,

I wonder if the solution provided by @cmallonee works the same with 8.3

I have a header with a breakpoint container containing two flex children: a small one for phone size, a large one for larger devices. How to send a message to a docked footer so that I can show/hide it depending on the header’s size?

I found a useful thread for listening a message on the docked footer, but how to send it?
Any way to toggle visibility of a Shared Docked View?