This feels a bit obvious but... Can we not just lose npc icons for triple triad once we collect all cards from them? Or like, have a toggle for them. Because there's ton of npcs all over the world and I only remember a small handful of them. Which makes it difficult to go and play triple triad against npcs when I keep challenging the same ones I do know where to find... Like the ones in gold saucer.

Better yet, why don't we have a full list/gallery of triple triad NPCs in the game? Showing their location and rulesets and filters to search for specific ones. What kind of cards they drop. Would be also useful for collecting them as you wouldn't need to browse the card list and go one by one to see if you're missing an npc card somewhere.
For example if I wanted to do the "play roulette rules 100 times" achievement, the only thing I can do is just Google outside game resources and see where any npcs with roulette rules are.