That seems to me to be quite different issue. Just throwing invalid stuff on the ground in this scenario will avoid a crash but lose data. This seems much worse to me than the crash.

Throwing it away does seem extreme. Maybe something that indicates what's left over? In other words: result, leftover_kwargs = func(<some syntax for this>kwargs) or result = func(<some syntax for this>kwargs) assert kwargs == {'whatever is': 'left over'}