Latests commits should fix #1460, but I'm still in the process of writing unit tests for the new stage disabling behavior.

Okay, everything should be up and running now, with unit tests confirming that the simulation results are correct.

As to Issue #1477, functions as expected, no anomalies found.

Forgot to mention: this PR also fixes #1460.

Remember that you only get paid by the PR, so you don't gain by fixing too many issues at once.

At to Issue #1460, first, let me say that everything functions as described with no anomalies.

However, I'm not sure that turning off the sustainer, or turning off a mid stage (leaving an upper and lower stage on) should produce flight results where this cannot occur in real life and the results therefore incorrect. Thoughts from others?

Remember that you only get paid by the PR, so you don't gain by fixing too many issues at once.

It's only because the fix from #1477 already started fixing #1460 that I continued the work.

However, I'm not sure that turning off the sustainer, or turning off a mid stage (leaving an upper and lower stage on) should produce flight results as this cannot occur in real life. Thoughts from others?

Also thought about it, but I think that's more of a "if something bad/unrealistic happens, that's on the user for inputting garbage", so not something we should account for.

There are some intricacies that will need to be documented for users, but I really like being able to see what effect each stage has on the flight.

Functions as expected, no anomalies found.