[Alneyan]

And it is what shields are for as well, since you cannot board a shielded target. You would need to put Shield Depleters (and a lot of them, just in case) on your boarders as well, and the build time reaches at least two turns then. (Assuming you have a Space Yard III and good construction rate bonuses, so it will likely be more three turns)

My understanding of the SDD is that the boarders cannot know about it, and so are willing to try their luck at capturing this ship. How would you know before boarding the ship that it can, or cannot, self destruct? At least it explains why your crews are willing to get killed by triggering a SDD, if fanatism isn't part of your Empire.

I will admit I would prefer if the self-destruct didn't always happen, and a mean to disable this device would be useful as well. Since the SDD is supposed to overload the engines, thus destroying the ship, how can it do so when all the engines are gone? And perhaps boarding with the intent of actually capturing the target may occur then. (The only use for boarders being to trigger the SDDs at the moment, unless you are very lucky and manage to take down the SDD without damaging the ship too much)