Interface ChessEngineAsyncOptions

plies to search; three stays the default - a worker is an optimization, not a license to raise depth

root moves scored at once (default: hardware threads capped at 8, else 4)

hard cap on visited positions, applied to each root move's search: every subtree is exact within the same budget the synchronous search gets as a whole, which is what keeps the chosen move identical to search inside the budget

aborting rejects the search and terminates its workers through threads.spawn