Anyone can be your Mackenzie friend, they cannot talk in court. They can make notes, Get someone you sound like you need it. You have to apply on the day of the hearing.
You need to be stronger, walk in their and ask to speak first. Do an opening statement and say this cannot be a final hearing due to the fact you get 6 hours of contact, you have had all services involved and background checks on you and your partner, drug tests are clear (?), alcohol tests are clear, mental health clears are good (?). The court has no evidence, your ex has no evidence and it is obviously a smear campaign against you to separate you from your children.
Explain how you have complied, how it has cost you a fortune but you don't mind because you love your kids and want to spend time with them. (Your ex will bring up the lose of house, so get in there before he can) explain you would sacrifice anything including your house which you have done to fight this tactical mission your ex is on.
Also demand more hearings so that you can rebuild contact at a pace suitable for the children. Demand any other costs are paid by ex or at least 50/50. Maybe @familylawsolicitor knows if you can get any costs back if they are all negative.
Each time you point out something your ex has accused you of with no solid contact say "with no evidence". You need to repeatedly point this out, build your case and point out all you exes lies.
You need to get in front of this and calmly but firmly argue this in court. If things are as you say they are you shouldn't be on the last hearing.
Take in a statement saying the same read from it and ask to add it into documents/evidence. You need it all on paper, you need a copy for court, your ex, you and your partner if he is also a party in the case.
Don't forget to label it with all the hearing info and numbers and sign.