Hi,
we are individuals. If you want to have more muscles, you have to stimulate them. But how? Each body responds differently. It's true that many things are in common, but you have to find the right kind of stimulus to get more muscles.
The same with your eyes. While someone can tolerate a little bit more blur, the other one can't.
You say you use your reduced prescriptions "sometimes". What do you mean?
Important rule: You need clear vision most of the time. Ideally, you would be at D1 (your far-point) and then occasionally see the beginning of D2 (a slight blur immediately after D1, maybe you wouldn't even notice it if you did not pay attention to it) whenever you feel for it.
Again: most of your time, you should see clearly. Better for your eyes, for your brain and for you also. And then, whenever you want to challenge your eyes a bit, go to your blur horizon (from D1 to D2) and try to clear up the blur (close-up or distance vision). Prescriptions help you as you can create your own blur horizon (how far do I need to see clearly?).
So just wear enough prescription that you see clearly up to that distance you look at and then occasionally challenge your eyes. Clear vision is not a bad thing. Extended close-up (with the wrong prescription) is what you do not want.
Kind regards,
Hans