Just a little preview. I've overhauled the advanced block replacing feature. It's basically a programmable converter now. You can add a rule set and apply it to a all prefabs at once. Should provide a much more convenient way of converting prefabs than the xml-based converter once it is finished. Could become interesting when A18 spawns.
This and other (unfinished) experimental versions of the editor can be downloaded from
here (64 bit only). I am too lazy to link them here or to make a 32 bit version of each experimental.