I just went though this complete exercise a week ago on my new to me 2019 GX460 that I've had for 2 weeks. The dealer put brand new Michelin Defender LTX M/S tires on it. Pulled into the driveway which is a long steep paver brick and slid in the fresh snow. Twice, once in the morning again in the afternoon. I've had a lot of tires in the 50 years that I've been driving. The one thing that scares me the most is losing control due to snow and ice. Seeing how all of the tires you mention are snowflake 3PMSF tires I'm guessing that is also in your needs analysis as well. Certainly is at the top of my list of needs. Maintain positive control at all times in all conditions. At least as close as possible.
In my search I expanded it to 17" wheels and in the end that is where I went. The TRD Pro wheels are 25 pounds, the stock Lexus wheels 32 so you save 7 pounds. Which I made up in a heavier tire but star of end result is the same weight as stock or close to it. I also went up an inch to 265/70/17, one inch shouldn't require a recalibration from all accounts I've read, if it does so be it. Will hopefully know in a week or so. My main concern is fitting it in the spare tire location.
Tirerack as mentioned above is a good repository of users real life evaluation of tires. Not the only one I use but it is a start.
The BFG Trail Terrain T/A you are thinking as your primary tire at this point is an On-Road All-Terrain tire and Tirerack puts groups of tires from the same category together so that you can compare them. The BFG Trail Terrain doesn't rank very well in snow and ice and is in the
middle of the On-Road AT tires category.
The other tires are Off-Road All-Terrain and while you may think they are overkill I would say it depends. As long as they aren't too heavy and aggressive they can be decent for highway comfort with good manners and quiet, well somewhat. They will vary a lot based on the tire. The rankings for
Tirerack and Off-Road AT tires is here.
The Falken Wildpeak A/T3W seem to be a clear leader and choice even with other reviews such as at Discount Tire. Also in those rankings is the KO2 which you listed as well and came stock on my Taco Baja T|X and I agree with the reviews. Great all around tire except for comfort and noise on highway. Also in Off Road AT category is the FIRESTONE DESTINATION A/T2 I had the original A/T and agree with the reviews again, it was terrible in the snow and ice.
I ended up going with the FALKEN WILDPEAK A/T3W 115T SL 31.7” and 17" TRD Pro wheels. Which are only 7" width so could be just a touch taller when mounted. Weight will be ~1 pound from stock tires and wheels. Still waiting for the wheels to come in so have no actual experience with them. But I am cautiously optimistic after researching the hell out of them. And the reviews on here as well.