Try playing around with all of the white keys EXCEPT for F natural, and instead of having F natural, use F sharp. See if you like that sound! It is called the Lydian mode. It is an extremely powerful and ancient musical scale!
But the only problem; whereas before I randomly played notes until it sounded well (white notes), I can't do it now. Or maybe it's because I need to practise more. Because you can't just do random notes in the Lydian mode, because if you do that, chance exists that you accidentally hit the f natural key.
Every scale, arpeggio, chord (or part of it - if it is a big chord) has a shape or a structure of shapes which you should first be able to feel and recognize in your hands as a block/chunk. As long as you cannot distinguish the shapes of different scales in your hands with eyes closed (basically two positions that repeat themselves), it makes not much sense to practise the separate notes/fingers in those scales. D, E and A triads, for example feel the same in your hand (white-black-white). B is the best scale to start (two groups: one white and two black - one white and three black), and it feels like no other scale in your hands. This principle is called "proprioception", and it is much more important for a good technique than repeatedly drilling your fingers.
This is usually the most effective solution to the problem of reluctant fingers.
This makes a few times now I've seen your posts on the hand shaping issue and I like the concept! It gives a bit of a fresh view to what we ultimately end up doing after years of practice without realizing it. With this in mind up front, I could see faster gains to keyboard control. I must read more about this, because I literally had not thought of hand positions in this way till now.
Just to make sure: you don't practise separate fingers anymore. All you do is "chunk" passages with the hands into comfortable positions. No stretching beyond natural limits! No excessive pushing, etc. Actually, it's an exercise for the brain. Nothing physical or athletic. It's sensory, tactile.
One element I forgot to mention in this approach is the following: