Have gunboats and up do a reasonable amount of damage to all targets within range of their final explosion.
The damage should be mostly hull focused as it would be caused via shrapnel and remnant energy isntead of specialised anti-shield weapons.
First draft proposal numbers:
Shield damage = 1/20th of total hull
Hull damage = 1/10th of total hull
So upon death a 100,000 hull (total) ship would do:
10,000 hull damage
5,000 shield damage
This would be enough to have most people concerned but not ruin your day by having people suicide bomb you.
Range:
The range should ideally be within 1k, this might seem a little large but an object in motion stays in motion...... so bits of flying metal could realistically travel much farther.
The real reason for this though is so that pilots "going down" with their ship will have enough space to not have to risk bumping enemies to deal their final blow.
Ship classes:
I think the game already does a great job of showing how larger vessels go down, once the hull is empty it's not an instant pop. This should be applied to all ships that have the lasting death animation.