I think Elmer would be floored with the improvements in every area. Laugh no I don't think so, he would probably have an issue with the distance shots are being taken today, since back then 500yrds was a damned long shot. The old school conventional thinking still applies for sure when your using the older calibers in the old school method. SD isn't the end all of anything never has been, just like BC it's an indication of possible performance relative 1 and only 1 area of bullet performance. You take 2 bullets of the same caliber and same bullet weight, with bullet A being cheap mass manufactured bullet and B being carefully engineered, with a tapered jacket, and construction being very tightly controlled at every step you will get 2 very different performances at every step of bullet performance. Be it exterior ballistics or terminal ballistics. Even though both bullets have the same basic design.
I do remember cor locket bullets very well, and power point, power lokt. That's all my Dad would buy when I was a kid, what ever was cheapest, I also remember him having one blow up on a spine shot on a cow elk, and proclaiming that a 270 was no good because of it. An issue I've never ever experience since I started reloading, and learned that bullet makers are very good at making a better product.
Uhhhh Elmer Keith was the original long range guy. What would scare him is the lack of understanding how bullets actually work. SD is the end all when you are comparing similar construction. No you will not get different results from one "engineered bullet" versus a mass produced one if they are built the same. Add in differing factors and yes there is a diff.
If we would just use some common sense with bullet weights all this other crap wouldnt matter.
The bullet manufacturers have loaded peoples heads with a bunch of crap. Its funny to me that a basic design thats a 100 years old still works very well when common sense is used. Trick bullet construction has caused people to forget what works. And I guess an edge with a 300 smk is old school. Bullet builders have spent 30 yrs trying to disprove science. They have done a decent job of it but using some old school common sense will make these newer products work better also.