Imo the Beldum catch rate actually based on nintendo pokemons(?) is a bit to low. 0.4% on full hp for a stage 1 pokemon without evolution. We can't false swipe him coz he uses take down move that deals him recoil dmg, so that makes him harder to catch. Even with sleep he has 1,56% for catch. That means most of the time he will kill himself with recoil or struggle if we use a normal pokeball, Even when we use ultra balls we still have +/- 2,5% catch rate. This pokemon is quite rare anyway so when we encounter him and and he faints by strugle or recoil it's really annoying.
I suggest to give him at least 5-10% catch rate from the start.
Games should give fun for people not make them nervous, and frustrated.