I have recently been experiementing with the monte carlo simulations which has been very informative.

I kept adjusting my expenses so that in my basic withdrawel scheme, I had very low chance of running out of money (or at least that is what I beleive these charts from the simulation results are telling me). In the net worth exluding properties chart. The median line is always above zero, and the dark blue are just touches the zero line just before the final year (93).

So then I run Legacy with a goal of zero, (which creates a large legacy expense) and then I run another similation on those results. These results appear to indicate that I will have a few high likelyhood of running out of money well before my last year (93). In the networth excluding properties chart, the median line cross below zero around 73, and the scenario line crosses below zero around 86. The wallet balance median line is also below zero around 73, and the scenario line goes below zero around 83. 

Is this the correct interpretation of these results?

Would it be possible to create a Time Machine option where you could choose your legacy but also run the simulation to ensure you are maximizing the withdrawels, but also hitting (at least) the median in the simulation?

 I think you are interpreting the results correctly. You can see that adding a large expense would not surprisingly increase the chance of running out of money in volatile markets.

The Choose your Legacy tool, finds the level of expenses in every year such that you leave a legacy of your choosing AND not have a cash-flow problem, that is not run out of money. However, that is calculated based on the rates you set for investment growth, interest rates, and inflation rates.

The Choose Your Legacy tool can handle those set rates changing in every year, and it is possible to run it on rates coming from the market model for simulations. You can actually do that now. First, in RATES/YIELDS/CURRENCIES you can Set-up new Market Simulation. Then you can choose the option to  Run a TIME MACHINE with Market Model Simulation. You will then have the option to run the Choose Your Legacy tool on that run, it will use the same simulated rates.

So I suppose we could run Choose your Legacy on each of 100 simulated runs and then report an average (or median) value for the Legacy EXPENSES to add. Or something like that, as it will take some thought and experimentation to determine how best to report on the results. The Choose your Legacy tool algorithm runs the TIME MACHINE many times itself, and it's not possible to know in advance how many runs it will take. Doing that 100 times could be very slow.

So the short answer is yes, it's possible but not trivial. I will look into it but it could take a while.