AsyncCursor.cs KillCursors(Async) methods has hardcoded 10-seconds timeout that is applied for channel resolution only and ignores provided cancellationToken, when killing cursors operation itself respects cancellationToken and do not restricted by that 10-seconds timeout.
We should investigate where that 10-seconds timeout came from (is it spec? some issue?) and check if it also should be applied to killing cursor operation too.