Sad to say, but some folks don't / won't service brakes on a trailer. And some don't even care about trailer braking laws. Hence, the reason why some regions want to apply year Trailer brake inspections. Thus, forcing trailer owners to apply trailer laws (and good braking maintenance habits). Sad to say but true...
When it comes to trailer brakes, I don't think about my regional laws. I think about "safe towing" first. For my Tow Vehicle, it can pull huge amount of weight but it doesn't have specs to "safely" stop an attached trailer. For my TV and Trailer combo, any attached trailer over 2,000 lbs needs brakes (on the trailer) - even though my local law says 3,000 lbs is the limit. With 2,999 lbs attached trailer, my TV is pushed around like a rag doll.
For my previous used TT (19 ft with 2 x axle design), I simple installed inertia brake controller in my TV, replaced trailer's older age brake assemblies, replaced its rusted brake hubs and installed much better STAR design 10 gauge wiring. re: 2 x 10 Gauge wiring to each wheel hub. IMO, this STAR design wiring should be minimum factory specs.
This worked for my previous used trailer. Recommend for your used trailer as well...