I know that to get better image quality often requires aspherical lenses, which are expensive to make, so at some point it becomes non-economical to have a lot of aspherical elements in a camera lens.
However, let's suppose that a photographer wanted to commission a custom lens from one of the companies that make such lenses. The cost of this would be in six figures, maybe $150,000 if we add in lens design costs, something like that. Would it be possible to significantly outperform available stock lenses by doing this? By "significantly outperform" I mean achieve a full stop of additional light transmission while holding equal to or better to a comparable lens in sharpness, distortion, vignetting and chromatic aberration.
For example, take the Zeiss Batis 25mm f/2 Sony FE as the comparable lens, which DXO mark calls the highest scoring wide angle they have tested. Would it be possible to commission a custom lens that have similar performance, but be full T-stop faster?