I agree, especially regarding the documentation. I was trying not to be too negative, but using Lambda is an exercise in frustration because of API Gateway.
I hope they hook up the new ALB service as an option for a Lambda proxy.
Personally I wouldn't care so much if they called it "AWS Gateway Beta" or something. That its limitations aren't advertised, leading me to waste time trying to figure out what I was doing "wrong", is what frustrates me.