I would suggest harsher nerfs to Kleptomancy. I don't think it's the potions that are the problem with the keystone - it's the fact that each item sells for 30g or more, except for the mana potions and Elixirs of Skill. With literally 3 pulls from Klepto, you're not only getting the on hit gold from the rune itself or the bags of gold, you're ALSO getting about 100 more gold from selling the items AND you're not even that punished for NOT selling the mana potions, as they are worth considerably less than everything else (15g). That's a MASSIVE surge of gold advantage over your opponent in lane, so it's no fucking wonder why Gangplank and Illaoi and everyone else abusing it are able to snowball crazy hard against everyone.
They either need to remove Kleptomancy, or do one of two things to it. Either the plundered items sell for 0-5g each, or either you don't get plundered items at all, and just the extra bit of on hit gold. Combining that much gold generation together is just absolutely absurd for doing nothing but spamming your spells. Supports literally had their items get quests added to them and got Ancient Coin reworked in order to make their gold generation more engaging, risky, and entertaining. Now, of course, it's all getting nerfed in no small part to the extreme gold advantage that Ancient Coin/Relic Shield gives non-support laners when they pair it with Kleptomancy. So seriously, get rid of this fucking keystone. It's breaking the game, and Riot is seriously doing that shit they do where they nerf everything around the problem and not the problem itself.