HI CCP,
So sorry to hear about your situation. My reply might be too late now as I just found your post today.However I just wanna share my case.
My case is exactly the same as you. I got my nomination refused in June2018(Ens186 Pastrycook transits from 457). The reasons of refusal was that there was insufficient evidence (receipts, a written report of the training outcome) to show that PR or Citizen were giving training. After having consultations from 2 migration agents and 2 migration lawyers,then I decided to reapply as those migration specialists said there is the best option for me so far. The positive point for reapply option is that the laws have chance. So.if you lodge a nomination application after 12 August 2018 the case officer are now not required to assess the training benchmark requirements as all businesses that nominate permanent or temporary staff must simply pay the training contribution charge( $3,000 for business with a turnover less than 10 million.
Anyway my case still has risks as the refusal decision of the previous nomination is on record and it could be adverse information and this can affect to the new nomination so the best way to do is providing a strong submission about the previous training issue. Or if I'm lucky , the case officer might not give weight to the training benchmark issue on the record as it has been discarded by the new laws. Finger cross and always have a good hope!
What I want to tell you is that don't just stick on one migration agent but seek a lot of second opinions from several agents or even lawyers to ensure you get the best solution. Good luck!