Yes they are! There are no additional fees after you agree to the terms with your creditors.
A Licensed Insolvency Trustee works with you and your creditors to reach a mutually agreed upon payment plan (like a referee) that sees the creditors receiving a portion of what’s owed. The Trustees fees are included in the portion that the creditor is to receive. Essentially the creditors are paying the Trustee fees for the service of collecting their debts for them.