Basically jquery seems to work, but what puzzled me first, is that it was not able to select DOM-Elemets inside my own components. It turned out not to work selecting sub-components if they belong to their own namespace like e.g. force:inputField.
Currently due to a bug force:inputField bound to a multiselect picklist-field renders in HTML as a disabled select.
So I have a
<select disabled="" ... > somewhere in my components sub-DOM - and I know that for sure.
Now I put
console.log( $("select:disabled") ); in afterRerender().
Having the critical update disabled, I get the expected result, like:
After enabling the critical update, I get only
Object[ ] - so jQuery could not see into the DOM created by force:inputField. This is caused by Locker Service and as far as I understood a feature and by design.