With DE work, using low weight seems to be a better fit. First, it is recommende 50-60% bar weight plus 25% accomodating resitance. So at the top you're hitting 75-95% at the top.
For people who aren't naturally explosive or come from a background of controlled/slow rep speeds, this helps teach them to keep pushing. I see a similar analogy in tennis or any ball sport. A lot of people touch the ball and then stop at that moment and can't generate pace. But, when you touch the ball that is the time to accelerate. For me, DE work has taught me to keep driving the bar even after my "sticking" point.
Yes, with heavy weight rep sets, you'll have to keep pushing hard but usally on the last few reps compared to the first couple reps.
Also, I've always thought of DE day as a way to generate as much force as possible with the lowest weight possible. Generate your 1RM force with 60%. And this might be time dependent. Being able to generate this force quickly can help you drive through heavy weights. But if you don't have this skill, the speed work will teach you.
Prior to some DE work, I used to train with the typical 2s concentric and 4s eccentric. It seemed like I'd get stuck at weights in an all or nothing fashion. Then with some DE work, I felt I was able to drive faster and better with heavy weights.
In regards to frequenlty switching exercises, I think you have to find a happy medium between practice (making neurological adaptations to be stronger--something like Sheiko) vs. building strength with akward/different exercises. In a sense doesn't all the practice make it easier on your body to squat which will mean moving heavier weights without more muscle? But to build you need to hit other pathways and fibers that force other adaptations besides neuro. I don't think this is absolute, and I think both extremes still work both muscular and neuro.