I agree with the majority of your post; I’ve always thought it best to hit as many possible points on the force/time curve as possible. But there is some truth to the specific load being used when improving power endurance. Those training for combine-like tests for bench press know that you need a lot of reps around the weight you’ll be tested at. If testing at 225, you should have a majority of you reps in the 205 to 245 range.
However, as you pointed out, even when training for an endurance test it would be best to spend the least amount of time required to build that endurance, and the remainder of that time building limit strength. A 405 bencher will outperform a 315 bencher in the 225MR test almost everytime, regardless of power endurance issues.
And as your quote at the end mentioned, none of this is new. Training becomes more specific and focused as the plan progresses.