Wow, Thank you for all the responses! All very helpful. I am going to start by looking into surge brakes.
Just to add more details from my original post. I am in MA and would be towing the trailer in MA and neighboring new England states ( NH, ME, CT, RI, VT). All these states seem to not require brakes for trailers under 3000 lbs.
So it stands to reason, that if we have a trailer that is 1700 lbs and had brakes that they don't need to be connected to be legal. However, the smart thing would be to use them if they are available.
Some of the possible towing vehicles (cross overs, mid-size SUVs) have notices in their owners manuals that say "All trailers towed by this vehicle over 1000 lbs must have brakes" but have rated towing capacity is in excess of 3000 lbs. Is this the manufacturer just covering their tails or is there real reasoning behind these statements? I have heard many stories of cross-overs and mid-size SUVs towing over 1000lbs without problem.
Thanks again,
-Andy