I read carefully this thread, and others, but I'm not talking about esoteric or "crazy stuff". Esoterism and "crazy stuff" is the grave of rational and good audio technology.
Quite frankly, why be interested in buying a headphone like this with such a low sensitivity, made by an unknown company which will probably stay long under the radar, if by chance it will economically survive ?
There are plenty of very capable headphones with reasonable sensitivity out there, at any prices, made by plenty of very capable and well established, old or young, audio companies. You don't need fancy amps to drive them well.
I don't mean that Topping, SMSL or others are fancy, they make very good products indeed (I own an older Topping myself at present), but they're surfing on the trend of ultra good theorical performances, way above the audibility threshold, while the products ergonomy, the services and the reliability seem more and more questionable, because they flood the market with too many products. How maintain a good quality control with so many references ?