I’m borrowing a wireless unit so no brake controller needed.It shouldn't be an issue. I have a 7-pin on my Gen 3. It only adds a power (I wired direct to battery - fused) and brake controller. I skipped the reverse lights, my trailer doesn't have them.
You didn't mention it, but you will need a brake controller. I have a Tekonsha, don't remember the model. It works great.