if your going to be doing wall charts you might want to look at graphviz and that file format as an intermediary. it's what gramps uses. I haven't played with it much but it looks good. the advantage is that the tree's can be edited after output so things can be adjusted after generation but before printing.
As a stop gap before this is implemented it might be OK to direct users to other tools...
I was browsing the list to see what the devs were working on. someone might want to make this title more descriptive. I'd do it myself but don't have permission.