I've had my Spathiphyllum wallisii for three years now, and I still can't quite figure out its watering rhythm

I've had my Spathiphyllum wallisii for three years now, and I still can't quite figure out its watering rhythm. It droops dramatically when thirsty, which is convenient, but I swear it's just testing me at this point. Mine sits in moderate indirect light and seems content, though I've noticed the newer leaves are smaller than the older ones—probably a sign I should bump up the humidity or fertilize more consistently. Has anyone else struggled with keeping the foliage size consistent on theirs?