Similarity is a starting point
A familiar price path makes me stop and look closer. But I want more than a convincing resemblance: I want to understand which parts of the structure match and what happened in the examples that went another way.
Keep the comparison honest
A historical analogue study compares a defined observation window with earlier windows. The comparison rule should be explicit, and the periods after each match should remain outside the matching window.
Inspect the uncertainty
Inspect multiple outcomes, the sample size and the selection process. Overlapping examples may not be independent. A projection is most useful when its uncertainty is visible.