What other advantages would I get from using Bill’s tool that those don’t already give me (so if you wanted an invitation to evangelise, there it is!)?
It's just easier to understand and use than Apple's Accessibility Inspector.
How in hell do you even lock the AI now? It's changed since El Capitan. Didn't it used to be Cmd-F7?
With UI Browser I point-and-shoot with the cursor and a hotkey to get to the element in the app I want.
Hit another hotkey to send a reference to the element to Script Debugger.
Then I have a script to transform the flat reference to a hierarchical one, which I find much more functional and easier to read.
I bought UI Browser v1.0 in 2005 after playing with it for a few hours. I knew right away it was a game-changer, and it's kept me from pulling my hair out when gui-scripting for all that time.
I'll post a gui-script I wrote to do Spotlight lookups in my ~/Downloads folder here in a minute.
The gui-scripting part took less than 5 minutes to write, because UI Browser made it so easy to get the reference I needed.