The problem with finding a new candidate for a birth relative is that you need to establish their ancestors to build a case with other individuals who may match up both through genealogy and DNA tests that align the adoptee with other cousins.
Moving forward with just one or two cousins who link up can be hard to justify the cost and drama of contacting living relatives from the potential birth family, only to win them over, get someone to take a DNA test and hope in a month they substantiate your claim.
It’s a hard sell both to the adoptee and the birth relatives you think fall into line. Shelling out a hundred dollars a guess and four to six weeks of patience waiting for the results can be a challenge; to say the least. So the idea is to try one’s best to substantiate things more. Especially if the non-ID feels like it contradicts the birth relatives, even on a small scale.
Taking every guess and pushing back the generations each time eats patience, effort, and stamina; especially if someone has already tried and failed at one or more guesses. In my own search I spent nearly two thousand dollars getting numerous DNA tests conducted and advanced testing to try and prove my Y-DNA and mtDNA so deeply that there could be no questions.
Despite all my investment, I found that only half my biological family wanted anything to do with me; sad and costly. While I spent to prove my case, I know that others have limits to their budget and grief they can absorb before wanting to put off the search until they feel up to the task at a later date. Being disenfranchised is no way to search.