Thank you for your question.
If the capsule is soft and not calcified it can be left alone. Having said that, I do find that there is a slightly higher risk of seroma if the capsule is left intact compared to removing it.
Some patients prefer to remove all of the capsule. This is certainly possible. I find it easier to do it in an enbloc manner, meaning the entire capsule and implant are removed as one piece. However, doing this will usually mean it has to be done through a larger scar.
In answer to your question, there is no hard evidence that leaving a soft capsule behind has any adverse effects.
Hope this helps.