Yes, I do actually. I wrote a nice documentation on it in fact: http://www.pokecommunity.com/showthread.php?t=236456
It uses the game's basic animation system, so it's pretty simple. To extend the table, you can just repeat the same pointer as before for each new trainer sprite you're adding.
Not everything from 900000 to 96FFFF is used, but thats the space I will utilise.
907000 is eventually going to be used by further move effects and battle scripts.
If you want to add anything new, start at 970000.
Oh right! Uh yeah I guess applying my patch, and then putting JPans thing again, should be fine. I haven't tested that but I guess it makes sense. It's not just the deleting, if you have changed the map sizes and the map names it might prevent the thing from being read in advancemap. My recommendation would just be to start again, and copy the maps and things over into the new rom.