Has Melanie Giles given you her opinion on whether the IVA is realistic?
In BR the judge goes on the information you give him. If you have investigated an IVA but feel you would not be able to meet the repayments and that it would ultimately fail then he won't (as far as I am aware) check up with the IP or creditors.
When you petition for your own BR then you take control and the creditors are informed that you are BR by the OR. They can then feed back to the OR but by that stage you have already been to court and are BR. (Far too many OR's and BR's there!!!)
With an IVA the creditors can have an input into the outcome and can ask for a bigger monthly payment if they feel you can afford it, or as appears in your case, the IP will ask you to forfeit things, like the course you want to do.
In BR you tell the OR what you earn and what you spend and as long as its realistic they accept it. You then pay back a percentage of your disposable income - not all of it.
See what one of the other experts think - I haven't heard of a creditor influencing a BR - one will be along soon.