Aggregates cross-validation results from `tune_survdnn(return = "all")` by configuration, metric, and optionally by time point.
summarize_tune_survdnn(tuning_results, by_time = TRUE)A summarized tibble with mean and standard deviation of performance metrics.
The full tibble returned by `tune_survdnn(..., return = "all")`.
Logical; whether to group and summarize separately by time points.