Can someone maximize his performance on low mileage?

You can maximize your performance using interval and time trials only. Running mileage optimizes your fitness to run for mileage, not race track distances.

considering the circumstances the furman-first training plan is the way to go. three runs per week (track repeats, tempo run, long run), all high quality and well thought out.

i used to run 70 miles and more and in my case it was wrong. looking back i would say that only true elites get the most out of high mileage. it is not a shame to achieve good results on low mileage, as the opposite really hurts. you can always do more if you need it.

three hard runs work. you maximize effort + recovery time. the training is hard and you will need for example at least one or better two days after a 20 miler at the given pace of the schedule.

i am not far away from 50 years of age and this kind of training has helped me to run regular tempo runs at 5:30 pace/mile again.

Is it possible to re-invent the wheel? Yes, in your imagination.

Do you need to run 100 miles per week to be an elite runner? No, but 25 mpw is a stepping stone.

You don't waste your time doing long runs if you're on a low mileage program.

Probably not without PEDs. 😉

Well it depends on the distance you are racing.

The shorter the distance the less miles you need to get closer to your potential.