What is your opinion about using ADM (Acellular Matrix Dermis) for mild nasal dorsum augmentation of 1mm?

Of course, I haven't seen your photos, and I don't know your entire history, But even when considering a primary rhinoplasty, 1mm is not much change, and might well not be worth the risk.After 18 months of frustrating slow healing with persistent swelling and oily skin and the certainty of another round of excess swelling and slow healing, it doesn't make sense to me to do another operation to get only 1mm of elevation. What if, after 2 years of waiting for the swelling to go down, you find that all of the graft didn't take, and you still need another 1/2 mm of augmentation? My two cents.

Without photos it is hard to evaluate your question. Supra-tip fullness is not usually treated with dorsal augmentation unless the dorsum has been over-reduced.ADMs are safe and effective but perhaps not as durable as native cartilage grafts.  Review all the options with your surgeon.  If he or she has had only limited experience with tertiary rhinoplasty you may want to get a second opinion. If you elect to have the ADM placed it will be soft and natural and should not cause long term complications.