Thank you for having them reconfirm what a few of us already know. I bet they recommend people follow their instructions and not try reinterpreting what is very clear to try to make it fit their narrative.
I have found that is usually the case.... same with engine oil threads, gear oil threads, all kinds of things for some reason some will always want to do it differently
No. A UPS that has active power balancing and monitoring circuitry and an almost-zero percent chance of being involved in an automobile accident is not at all related to a winch mounted on the front of an automobile and hardwired to a battery.
Like I said, if it makes you feel better run a switch or a solenoid or a disconnect plug, or fuse or whatever combination you want, Warn still doesn't recommend it just because they sell it. In fact they say exactly what I've always said, you CAN run one if you want to. And no manufacturer recommends fuses or breakers period.
The circuit isn't on until the winch solenoids are activated. Are there any other 400A+ circuits on the vehicle period? In a vehicle where the battery is remote mounted the battery leads are far longer than winch leads... and still unfused. Your typical DC class T fuse will run at 200% for a full minute. If it's sized for max winch draw it will never trip at max CCA.
The starter is wired directly to the battery.
I just checked because my CTS has a trunk mounted battery. It does have fuses. There are five fuses in the distribution block that sits right on top of the battery. My Silverado also has fuses even though the battery is up front. I believe the JL also has one of these fused distribution blocks right under the main fuse box doesn't it?
Where's the single 400A fuse though? Where's the factory installed winch with a cutoff switch or a fuse? Why don't they just run 1 big fuse on the battery positive terminal for increased safety? Because any fuse big enough for the full load would never trip. Sure you could try getting creative with a class T and run it undersized on the hope that you never pull the full 400A rating of your winch long enough to blow it. I wonder why nobody aside from the paranoid on the internet does it? Why don't winch manufacturers recommend them? If it was nearly the safety concern or as easy as the uninformed on the internet make it out to be they'd have some liability waiver if you installed their winch without a fuse in the install manual. Instead of 1 big winch you could run 4x 2k pound winches with 100A fuses I guess?
Far left in this pic:
Lots of guys run 250A fuses on their winches and never have a problem. You would most likely overheat the winch before you pulled enough amps for a long enough period of time to blow a 400A fuse...what's the contactor in the Zeon rated for? It's not 400A continuous I know that.
That's a 400a rated distribution block, not a fuse. Even if it's a fuseible link they often cause major damage when they melt when they are that large. I'm willing to bet there are far more unfused winches than under fused running 250A fuses on 400+A rated winches.Far left in this pic:
Lots of guys run 250A fuses on their winches and never have a problem. You would most likely overheat the winch before you pulled enough amps for a long enough period of time to blow a 400A fuse...what's the contactor in the Zeon rated for? It's not 400A continuous I know that.
Actually, I'M the one who should be able to get that answer. I'll ask and report back.
Have had and saw a number of brands fail to a point of not recommending some certain brands other than select models. Hard to believe I had a old H.F (pre Badlands) 8k winch that refused to quit. Slow as hell but always worked, I finally found someone to give it to. 
Actually, Ramsey winches come with a fuse bar on the power cable to protect the winch and vehicle from possible damage.
