Maybe Fund Manager could begin to handle these (big) topics?
Plenty of ideas here: https://www.portfoliovisualizer.com/
For example a backtest portfolio feature could be useful:
https://www.portfoliovisualizer.com/backtest-portfolio
(Implemented in Fund Manager, we could imagine a feature to pick the portfolio state at a specific date in the past and see how the portfolio would have performed until today if kept unchanged).
Ideas for future developments...