This was referenced here
http://game-editor.com/forum/tp-2440-RP ... ditor.html
But I thought I would expand on it a bit. This is not only a major issue for RPGs, but also an issue for any other type of game of decent size. Multiple maps would speed up loading time, processing time, and would majorly aide the ability to write games. 90% of games are made with multiple maps, both platformers and others. Game Editor is simply not scalable enough without this.
Writing a large game in the current format takes a lot of work to get around this issue. Writing even a mid size game takes a lot of load time with all one map, and also majorly increases the ram usage, and CPU usage on a given platform specifically because it has to deal with the entire game at once. This just isn't viable beyond a certain point, and Game Editor games do not do well on older PPCs for this very reason.