Wheeler-Feynman absorber theory vs Asymmetry of Radiation?

Maxwell equations have both retarded and advanced solutions, also their convex combinations are allowed:

Wheeler-Feynman assumes symmetric 1/2-1/2 contributions, but e.g. energy loss shows asymmetry instead - which should depend on the boundary conditions, e.g. Huw Price says it is because of more absorbers than emitters ( https://link.springer.com/article/10.1007/BF00733218 ).

Seems nearly everybody assume 1-0 only retarded instead, but maybe it is worth to verify experimentally, especially that emitter/absorber imbalance might not be perfect? ( https://arxiv.org/pdf/2512.20692 )

Where do you think this Asymmetry of Radiation comes from?
Should it be really perfect 1-0?
How to test it experimentally, distinguish from e.g. 0.999999-0.000001?