Eventually I found https://github.com/Tonius/SimplyJetpacks/wiki - is this the most up-to-date information?

I'm not sure, but if you have jei, it is self explanatory.

"Emergency Hover Mode" isn't self explanatory at all, especially since it can be turned on and off even on jetpacks that don't support it.

Emergency Hover Mode protects you from dying to a fall

If you have it on

We are in the progress of making a more detailed wiki on this repo