Can I get multiple Backtest results from Autopredictor Amazon Forecast

Hi, I'm experimenting with various forecasting algorithm and comparing them on multiple backtesting. However, Autopredictor only gives me the backtest results of the last forecast horizon. I'd like to compare autopredictor and legacy algorithms based on multiple backtest results. It's not possible to get multiple backtest results from upgrading legacy predictor(set as multiple backtest) to Autopredictor. How can I get multiple Backtest results from Autopredictor like legacy predictors?

Thank you.