Yeah, sorry, I was only half-way joking (an English RS3 editor would really be amazing though)
If I remember right, the editor was a hot-mess, so you're totally right about it probably being easier just to build your own from scratch. However, I believe that one you found is what was used to create that massive RS3 hack that plugged in characters, custom music, and events from literally every SaGa game ever made (except SaGa 3).
I personally just want to go through and re-proofread all the writing though, because while most of it is passable, it's generally about as much of a mess as the original Secret of Mana. Plugging in new music for certain sections would just be the cherry on top so-to-speak. If I were not starting grad school this Fall, I honestly might actually be motivated enough to learn some hacking to take a crack at it myself
But yeah Seihen, if you WANT to jump into the abyss (no pun intended) of compiling an RS3 editor, I know I'd be super interested
--my posts were mostly just me venting as my more recent playthrough lol