I get a kick out of reading some posts of failures. Of course they all blame certain things.
I wouldn't expect my switches to carry the current for a full large consist on my RR, while I have high amp draws. I would run my own jumpers at the least. Most of my blocks are created so the switches are at the very ends. They may carry the current of a single engine passing over. They don't have to carry the whole train's draw. I don't think it's just one manufacturer's switches. I don't think there are many switches out there that can carry ten amps or more thru these small jumpers. I believe they're just intended to carry current thru the switch to prevent stalling.
Building a large G scale RR outside helps me learn how to handle current draws. Anywhere there's a weak point shows up real fast. There are many ways to fix these issues. The best is to learn before burning up stuff or creating failures. I've had a lot of experience from the later, though.