My great evil plan is I wrote all of that about Map() and Dim() hoping that you or others will play with it and come back with further details for the rest of us.
But no obligation. The best way to learn is to teach, and most of what I've learned about TARGET is figuring out the answers to questions for other people. Stuff I wouldn't have done just for my own needs.
Also, if you actually want to understand the btnidx, devdata, devicedata[], axdata, the joy1, joy2, joy3 etc. stuff... Basically how all the data structures work in TARGET (the magic behind all this), I have spent a lot of time understanding all these details. I mean it is all there, you just have to go through target.tmh and document the contents of the data structures by following how they are used and the mud starts to become clear. Now that I have done that, I am starting to write my own functions to do some of the more advanced stuff. Stuff equivalently complicated as the LIST() or AXMAP1/2 functions, or new versions of MayKey() for example. A lot of this is driven by what I did with my Train Sim World script.
But I would suggest any further discussion on these topics be placed in a new thread as we are kind of going off topic for this thread.