I didn't ignore anything. My initial post on this minhag was that it is totally fine. Just added later that if all of the haddasim are not kosher, I would be more hesitant to say everyone thinks it's totally fine.
I can't imagine that the hamon am taking dozens of haddasim don't include any possul ones.
Is minhag chabad to make a tenay?
Maybe you first take a moment to familiarize yourself with minhag Chabad before you make assumptions.
Sefer haminhagim states that we don't add Arovos, but
may add Hadassim, and mentions several counts (4, 12, 13, 26). IINM the Rebbe used 26 most years, possibly 36 on a שנה מעוברת, and in the later years.
For years there were very few people who actually added Hadassim (or had more than 4 haddasim). Then in the early 1990s the Rebbe encouraged the practice (and IINM suggested to add at least 3, will post source when I have it available).
Practically, if you look what "hamon haam" does, you'll see that most add a few Hadassim (so they have 6 or more), few have 3 or 4 while maybe 5% of the crowd has 36.
In recent years, I haven't seen Hadassim sold loose. Everybody buys pre sorted, so assuming one can rely on the Hashgochos on the sorting, they are all kosher.