Será que ter dois braços biônicos de melhor habilidade concede +20 para testes de força feitos com os dois braços?

Dark Heresy Second Edition

O bônus de +10 de cada arma para os testes de força feitos usando a pilha de braços um com o outro ao usar os dois braços para levantar algo?

Best craftsmanship bionic arms provide a +10 bonus on Agility tests requiring delicate manipulation and add a +10 bonus to Strength tests using the arm. They can be also used to store small items (such as pistol ammo clips) inside concealed interior compartments within the arm.

E esses bônus se aplicam a um teste de Heft, como quando carregando uma arma pesada de duas mãos e precisando aumentar o peso máximo para evitar que ela fique sobrecarregada ao carregá-la?

Heft
Athletes are also known for their strength and can lift great weights for short periods of time. As a Free Action, a character can make a Challenging (+0) Athletics skill test to increase his carrying capability for a single encounter. For every degree of success the character achieves, his Strength is increased by 10 for the purposes of how much weight he can carry, lift, or drag (see page 248), to a maximum modified Strength of 100. Hefting can only be attempted once, and if the character fails the test, he cannot try again until the next encounter.