For a backtest it would be great to see the greeks in the trade replay. In addition to VIX, Trade P/L and SPX add all of the greeks available in modelling. To reduce clutter you could give the user the ability to toggle on/off which greek they want to display but make them off by default.

For a portfolio backtest it would be nice to see a replay of the greeks on a daily basis, maybe say every 5 minutes.