And here is a perfect example what the Hamburger menu is actually for. Rather than moving the filter menu and collections buttons in front of the search they should collapse into child items of a Hamburger menu.
As for the search field itself in there if the header becomes too small it should collapse into a button with the search icon that when pressed would take over the header(causing other items to disappear while it’s active) and expand into a input box again.
As a convention the Hamburger menu is for collapsing Header menu items into a dropdown list in responsive design. Admittedly this is a convention for web sites and web applications first and foremost but it’s already made it’s way from there to mobile apps as well.
In the meanwhile in blender land the developers are discussing bringing a Hamburger menu into blender for the Top level application menu(file, …, Help) because they weren’t sure what to do with unconventional menu items that don’t exist in any other applications since they are the type of things that in nowhere else would ever have been added as menu items in the first place. Rather as I mentioned previously most of them belong in the preferences.
I’m sorry if I come off a bit ticked-off by this but I just don’t understand how this isn’t more obvious.