Synthetic oud is an accord, a blend of aroma molecules arranged to read as agarwood. No tree is involved. It is stable, repeatable and affordable, and it does not vary between batches.
Not by the opening. In the first ten minutes a good synthetic accord can be indistinguishable. The difference shows in hours three to six: an accord stays where it started and fades in one piece, while real agarwood loses its top and keeps going, smokier and drier.
Roughly one Aquilaria tree in a hundred forms resin in the wild, it takes twenty years or more before the wood can be harvested, and the genus is listed under CITES Appendix II.
No. All four extraits use genuine Thai agarwood, the same material beneath each one. That was a founding decision.