Keep the oil changed and maybe use a full synthetic additive like Slick 50, then drive it into the ground.
This. Drive it until it no longer will turn over. You won't cause any "additional" damage if the engine is already unrepairable, so might as well. And when that happens, tow it to a salvage yard and buy a new car.
I'm assuming it's a lot more than lifter noise if Kia won't even quote a repair. They make good money on repairs, so if they "pass", it's probably not worth repairing.