Hello and apologies for the delayed reply to a delayed comment :)
As mentioned elsewhere, I spent a four-day offline week-end (we have a bunch of short vacation slots in May-June in France), followed by a conference to which I currently participate. This means very little on-chain time during the last few days.
Anyway, here I am again!
You know what you are looking for, in advance. You limit the field of possibilities to increase the chance that you will encounter the particle you seek. Does it ever worry you that in defining your search you might be in a way undermining the legitimacy of the outcome? I guess not, because if you find the dark matter particle you will be able to present absolute proof about this very special 'missing link'.
In fact, this is not 100% correct. The main point is that we don't know exactly what we are looking for. And this is where it starts to get complicated: we need to try to cover all possibilities we could think about.
As this task is impossible, we need to make sure the results of the searches will be re-usable in the future, just in case we may need to use the legacy of the past experiments to test models that could be proposed much later. I am working on this item for about 10 years now. Progress has been made, but we are still very far from full re-usability...
Cheers!