[Feature Request] I have multiple knn_vector fields with settings.index.knn set to true, but it would be ideal if certain fields could use approximate k-NN search while others could only use exact k-NN.

[Feature Request] I have multiple knn_vector fields with settings.index.knn set to true, but it would be ideal if certain fields could use approximate k-NN search while others could only use exact k-NN. #649