Thanks for providing the Grandpré worksheet at http://bionsgadgets.appspot.com/ , BION. It’s much handier to use than the interactive one I made many years ago – I’ve never put in my time to learn to program user interfaces, and in something like this it really shows! I used yours to do the JF19 AC-1217 and you made it fun rather than tedious.
I wonder whether crib placement could use more of the available frequency information. I think it currently just looks at overlaps in the crib, but perhaps it could also usefully check frequencies. I know in a homophonic like this you can’t count on high-frequency letters much, but if you have a low-frequency like ‘F’ it’s unlikely to be one of the higher-frequency dinomes. One could also give votes up and down if other digraphs or longer are formed.
I’ve also been musing about better automated Grandpré attacks, hillclimbing on both the keys and (if any) cribs, perhaps fiddling the keys to make sure it always has a full alphabet of words off my “cromulent words” lists, again paying attention to frequencies. I haven’t tried anything automatic yet – has anyone else?