A Sinomacrops comes to you rather than the other way round. Stand in the open on flat ground with Chitin in your last hotbar slot, which is the only thing it eats, and wait: it will only take food once it has landed and picked you out. Nothing can be overhead, for you or for it, so no roof, cave, tent or platform saddle, and being under cover does not just block the feed, it makes the creature turn on you. After each feed it flies off, so follow it and wait for the hearts before offering the next one. Leave longer than fifteen minutes between feeds and it starts giving progress back.