This is exactly slinky braking you're describing right here. I'm sorry but if I had to ride like that I would go insane.
You just don't get it. Pulse braking, you're braking hard some of the time and completely off the brakes at the other times. Drag braking, you're never off the brakes, but you're applying less force than in pulse braking so you're putting heat into the rims at a slower rate. End of the day you put the same total amount of energy into the rims. Therefore it makes no difference what technique you use. Same temperature.
Applying the brakes doesn't put a magical blanket on the rims that stops them from losing heat. What you're saying is the same as saying, during the time you're sitting down to eat, you body is losing no calories. No mister, your body doesn't care if you happen to be eating at any given moment. It's burning the same 85 calories per hour all day long. Your rims don't care if you're adding heat to them at any given moment. They're losing heat continuously the entire descent. When or how you add the fixed amount of energy into the rims doesn't matter. The only thing that matter is the total amount of energy you put in. Drag lightly the entire time vs brake hard pulsing, doesn't matter. Same total heat energy.
Yes that's the thing about touring. You're always riding on unknown roads, by definition. Unless you consider riding the same loop every week around your house to be "touring"? The world has many countries, life is short. I don't waste my life touring somewhere I've already toured before. Therefore the road conditions are always unknown to me.
You have no idea what's coming up on the road. You can be bombing down a descent in a wealthy country with the best roads in the world, but there was a rock fall the previous week and it smashed a hole in the pavement. You have no idea what's in front of you.
I don't have the balls to bomb down a 8000 ft descent without touching the brakes. If you do, good for you. I don't think you're lying. I believe you. Enjoy your exhilaration. Try not to do a Fabio Casartelli.
Line of sight of course is a big deal, seeing far enough ahead to react, and to moderate speed to allow a reaction.
So we do have an idea of what's ahead, by looking, and judging things, always ready to change our speed or line or whatever.
But it's all about the time and place, and assessing the given situation.
And heck, we all have a million times more chances of getting taken out from behind by a texting driver---whether with regular tubes or TPU tubes.
But yup, life has dangers, most people think we are nuts bicycling touring on roads with cars.
Touch wood