So what's different about this modded L-6? It's no longer linear! Instead of having to play the same modes over and over again in east-to-west order, there's now a setting to make them completely random. There's also a setting of how many modes have to be completed to reach the wizard mode.
For those wondering, this is the Soren ROM from Pinside. I made a note of it back in the days but now that I wanted to try it out, all traces of it had disappeared from the net, save some broken links. Fortunately I found someone who had it and could make me this ROM dump.