if it is reusability of the decision logic that you are after, you could do it in a block

Hey Dorine, not sure how you would make this work with a block without potentially making a bit of a mess with JS to click hidden button inside the block etc. How were you thinking of triggering the block client action?
A block implies front end/UI reutilisation (this has nothing to do with UI). I need to reutilise a client action inside other actions, these can come in a variety of situations: 

• after clicking a button
• on after fetch
• an event 

I don't fully understand why the destination of a screen is not available in global client actions but available in screen client actions (it could just be an oversight or there could be technical challenges I don't know, hence this idea request).

The other alternative we have used in the past (although this comes with 1AO cost) is to have a new screen with the on ready logic holding that client action. We used this method to overcome another issue, to open these destinations on a new tab (because target=_blank does not work on client actions destinations switches like the one above so we open this new screen on a new tab and then the on ready redirects to the correct screen) --> https://www.outsystems.com/ideas/13085/destination-widget-with-new-option/