What is the healthiest option for explant without replacement, a capsulectomy or capsulotomy?

Although precise and meaningful device would require in person consultation, some general thoughts may be helpful to you.  
Generally speaking, unless the breast implant capsules have thickened and/or are otherwise symptomatic (or potentially in the event of a silicone gel breast implant), there is no indication to have them removed. On the contrary, capsulectomy can expose you to additional risks, such as bleeding and minimal size loss.
Having said that, I often remove a small segment of capsule tissue when removing breast implants with the hope that this maneuver will help with fluid resorption (and help prevent seroma formation). I usually use drains also. Generally speaking, what your breasts will look like after explantation depends on several factors such as: the quality of skin elasticity (the better the elasticity the better the skin will bounce back), the size of the implants used (the larger the implant the more trouble you may have with redundant skin), and the amount of breast tissue present at this time (which may have changed since the time of your breast augmentation).
Life experience since your breast augmentation procedure, such as pregnancy or weight gain weight loss, will potentially influence the factors discussed above. If you take these factors into consideration and apply them to your specific circumstances you may get a good idea of what to expect after the implants are removed.
Patience is definitely indicated after removal of breast implants; it will take many months for the skin to “bounce back” and for you to see the final appearance of the breasts.
I hope this, and the attached link ( dedicated to breast implant removal surgery concerns), helps.  Best wishes.

It all depends on the capsule.  If you have a soft capsule that is not thickened and not bothersome, then leaving it alone and closing the pocket is more than sufficient and appropriate.

It is very controversial as to whether the entire capsule is necessary to be removed. It really depends on the severity of scar tissue with deformity and the amount of native tissue still available for tissue coverage .