It’s not as adult as you might think . I found the manual a bit delphic (could be my limitations, not the manual). You just need to put the script in the “Toolbar” subdirectory of the “com.devon-technologies.think3” subfolder in “Application Scripts”. If you have the script icon in you DT menu bar:
(1) open your script folder:
(2) put the script in the Toolbar s/d:
(3) quit & restart DT
(4) right click on the grey area of the top bar in DT:
(5) select “Customize Toolbar”
You’ll see a window with a series of icons, including one for the script you just moved or copied into the Toolbar s/d (in my case, the icon named “Test”):
(6) As the instructions say, you drag it onto your DT toolbar.
If it helps, DT takes some of the pain out of splitting files (as Jim pointed out to me in January).
Wouldn’t that no longer be a problem if you are either setting the creation date or a custom metadata date field to the date of the subsequent decision? You can just sort by ascending date. In my Smith v Wilson example above, DT displays all the subsequent cases referring to Smith v Wilson in ascending date order:
Anyway, I think I see your logic. I guess the options are tagging, custom metadata, maybe a smart rule. If it would be useful for you to have an intermediate “bridging” linking note, you might find the Annotations inspector useful. I use it to make notes about cases with links to subsequent decisions to map lines of authority for a particular proposition.