Good work! Congratulations on developing this system!
One of the reasons why I abandoned the idea of splitting phonemes in our old discussion was because I’d be using two different Major Systems for different disciplines (numbers/cards/binary). This idea made me feel quite uncomfortable. Idk if this bothers you too, though.
I understand this is supposed to be a “cards first” approach, but I do think you could encode all 1000 3-digit numbers using this. Since there are 8 pairs of suit-pairs, you left R and F/V out, so you could use them when encoding the hundreds of numbers, but they would stay unused in card memorization. After this change, I believe it’s possible to pull a 10-digit binary system from this too by applying variable image stacking to binary numbers.
Btw, I thought you disliked variable image stacking, so I suppose you don’t have the intention to apply this system yourself, or have you changed your mind?