Hello and good morning Dan 
Thanks for your quick reply before doing some breakfast… I assume reloading of Keyboard Maestro‘s Engine would be the easiest part if the little one liners you shared here are doing its job without shutting it down.
The whole thing would be one PlugIn that has a configuration for new entries which would then be used to add as on my example to the Photos Application and then put into the plist for this action with the corresponding ID‘s so that I can when ever needed use the same action with another configuration to retrieve this new entry from the drop-down of the configuration and put it for example into a Keyboard Maestro Variable.
But maybe I decide to make more than one action for this - we‘ll see.
The not so easy thing is the part for the code that is able to see the updates for the various specific parameters and their options which will then update the plist accordingly to any changes.
Maybe I’ve to put all together into an onetime executable Applet for installing the stuff that’s needed including the Action(s) and for the purposes of deinstalling the stuff as well - that has to stay in the Applications Folder so that everything works.
This all is very new to me especially when it comes to the dynamic thing… that is the main reason why I created this topic. There are maybe many ways doing something like this but which one of them will be the one with the most less work to put into ?
When ever you’re reading this reply - I hope you had a great breakfast 
Greetings from Germany
Tobias