It's too bad it doesn't work in TSF (and outright crashes it). This limits what you can really do with this, since your level is basically 1.23-only.

It would be nice to see an implementation of this using the 1.24 level format, because those at least can't be opened in 1.23, and thus can't crash it. Also, anyone using this feature won't have to tell people that their level is "1.23-only", which as far as I know, has never been necessary in the past.