Without submitting DNA, at least you have the choice about whether or not to turn in blood-relatives, should the situation arise. However, If it is submitted in advance, the decision is being made that you will ALWAYS turn in any blood-relative under the previously-mentioned scenario

Yes in that super contrived scenario where you know for a fact that it will be used in crime investigations.... that is a fact... how would you be able to change your view on that? you're just stating a fact? That if you provide evidence that x person in your family did x thing then you are providing evidence that x person in your family did x tihng...

Could you maybe explain what kind of reasoning you think could possibly change your view here?

I would argue that loyalty does not have to mean cover-up of murder. loyalty can come with varying degrees and one could argue that loyalty could be broken over a certain situation, such as that person committing something you think is morally abhorrent and disgusting and deserves jailtime or worse.

However that gets canceled by your "unconditional" part which is another way to make your statement insane to debunk.

unconditional loyalty would mean that you would do literally anything to make sure your family wouldn't go to jail. even if that meant the murder of thousands of innocent people.

Although one could argue that maybe, loyalty does not in fact mean to cover up for something bad. it could instead mean loyalty to uphold a certain moral code in your family. and therefore your loyalty lies with making sure that your family is met with legal consequences if it strives from your moral code.