I barely remember this thread, not even kidding. Everytime an idea pops in my head regarding a possible memory system, I just post it as it forces me to articulate my intuitions in a precise manner. Since I have so many ideas popping in mind, I can’t remember all the systems I have posted.
I feel that discussions about whether or not a system qualifies as something, comes with the risk that conclusions are drawn based on subjective classifications that are not connected to reality. Tim, for example, puts a lot of effort in convincing people about what qualifies as a single piece of information (I don’t remember his exact wording). In my view there is no objective way to make that distinction. Obviously a 3 digit PAO system that translates a 9 digit number as Michael Jackson jumping with an umbrella in his hand is not a single piece of information that already existed in your brain as a unique idea before the translation. However when for example you have a single digit object and 2 digit person system, it is possible that every combination is as unique and already existing as a single idea in the brain as the images of a 3 digit person.
Regarding the block systems, I remember one system I proposed in 2020 that not many people seemed to understand or appreciate (What was I thinking?) 
: The super position 2 card system.