I've not done megaminx BLD yet, but since I have been working on it and have a method prepared I thought I would chip in, even though I'm not sure anyone will use it (at least my memo). I've mentioned before a few times (once in this thread at least) that I use a composite letter pair image system for memo: the first letter gives me an object and the second gives me a way to modify the image of that object. That makes it easy to cover the English alphabet, the Greek alphabet, and digits 0-9, which exactly covers all the sticker positions of a megaminx (a coincidence which still freaks me out a little). Note that none of the image descriptions actually alter quantity, but are other things I can associate with the numbers (such as 3=on phone, since there is a phone network called 3). I plan to direct solve, by setting up to easy 3-cycles, without worrying about inefficient memo since I don't need 2 letters per piece. Overall, the amount of information then works out to be similar to a 4x4. I'll need to do a few more practice solves, I'm finding it hard to track pieces, but I hope to be able to attempt it soon.
Slightly off topic: I'm now working on extending my system to encode 3 letters per image, then 4 letters. I love the fact that it will still be a shorter list to learn than a standard letter pair list, covers more letters, and is more condensed. Shame I'm not yet fast enough at BLD to make good use of it

. I plan to post more about it after I have learned it all and tested it out in practice. I
really like the idea of this system and I will probably mention it more than strictly necessary to see if I can get anyone else to test it. Does anyone feel like switching to it/using it when starting to use an image system?