I've made several variations, let me know which suits you best. Based on your feedback I am ready to create additional variants.
The main idea is that eccentric thumb position still works and could be better accesible (even for people with smaller hands).
Support: YES (tree), Infill: 15 % (grid).
I printed and tested it with a regular PLA but the result printed with flexi filaments (TPE, TPU, TPS, …) would be more anti-slip.
The author hasn't provided the model origin yet.