I definitely think that being independent from the agency itself is very helpful. The community will feel more comfortable filing the complaints knowing that an independent body will review and take action if appropriate.
Akwesasne being the 70% user of this port of entry is extremely important because it's unlike any other port of entry. If a traveller complains about a border officer, the likelihood of them having an interaction with that officer again is very minimal, but in my community, it's very high. If somebody complains about an officer's conduct or about the service they received, the likelihood of them encountering that officer again is very high. There's no other border crossing in Canada that would be like that.
Having said that, doing this outside of the agency is definitely helpful in ensuring that it's a fair and independent process and a process where the person who is complaining—and I would argue the officers themselves—can be assured that it's more of an objective process than an internal process.