The Tailwind has a very robust (30 amps each) six relay isolator in its Electrical Bay.
I had a plug and play isolator in 2001 on my first GL 1800. Always built my own isolators before that. The purchased isolator was used with a Hannigan Europa trailer. Three of these isolators failed, each in about 10,000 miles and all failed in the same way, the stop light relay welded shut and each time the brake lights remained on without my knowledge which is very dangerous as the driver behind does not know you are going to stop.
I finally made my own for the Hannigan and had no more problems. The relays we use are called "Headlight relays" and are very common in the automotive industry. they plug into a socket which makes them easy to replace. However, I have never had one fail.
You will find the Tailwind has quite bright taillights and the lights do not dim when the brake light is actuated. The system runs from a 12 gage loop direct from the bikes battery.
The system also has a remote battery (Gel Cel) in the Trailer's electrical bay that automatically charges on line when riding and drops off line to power the trailer only when the bike is shut down or disconncted.
This is a six wire system, Two wires must be 12 gage, the other four can be cat 5 wire or anything at all.
Making your own isolator with these robust relays is not hard, just time consuming.
Plug and play isolators do protect the bike and will likely not fail as often when not driving large filiment stop lights. They are compatible with the Tailwind system as long as the two 30 amp 12 gage wires are used between the battery and the trailer plug. The positive 12 gage lead is always fused at the battery positive terminal to avoid damage caused by an unprotected wire.
In any wiring added to the bike, make sure the lead between the 12 volt source and the fuse is the shortest possible and make sure the fuse can be accessed by simply removing the side cover, and not the seat.
One more thing, fuses that are the kind that glow when popped will carry enough current to drive a voltmeter and can cause considerable confusion to the novice when shooting trouble with the voltmeter or LED test light.
One of our trailer customers had that very experience.