Multiple extensions on UI components ... what about the order

We have here some UI components on which we add multiple extensions.
I wonder whether there is a reliable order when
is executed.

Let’s say we have a component on which we add 2 extensions.
Both extenstions add an element into the DOM on
Finally the element of the component itself and both elements added by the extensions are sibblings and the order of the elements matters.

We came up with a solution where we check for the existance of of elem_fromExtension1 in the #extend-method of exention_2.
It works, but it is an ugly workaround and probably must be changed if new extensions enter the game.

cheers, Christoph