Change in finances during a proposal
Suppose I enter into a long-term consumer proposal and offer my unsecured creditors X amount of dollars per month, and they agree to it. What happens if during my proposal my income substantially increases, or the value of some investments I had prior to the proposal (and these investments were disclosed in the proposal) suddenly jumped dramatically. What if I don’t want to double-up and pay off the proposal faster with this additional money ? Can the creditors come back and ask me to ammend the proposal for me to pay more each month ? Can they wait until the proposal is over and sue me since my net worth has increased ?

As long as your proposal was based on valid information and reasonable assumptions you do not have any concern. Once a proposal is accepted by your creditors and approved by the court the agreement is set in stone unless you have committed an offense under the Bankruptcy and Insolvency Act or defaulted on the terms of your proposal. This can be both a positive (as in your situation), or a negative (if your income was reduced).