As of 0.9.1 Mission Parameters are now configured in the Briefing map via the KISKA Mission Parameter GUI. It is very similar to the CBA addons menu in design.

To open it in the briefing, click on the Configure Parameters button at the bottom of the screen. (SEE NOTE 1)

Most of the controls are self explanatory and have tooltips for use. The only important button to note is the Commit Staged Changes button at the top. Just remember to use it to actually broadcast your changes before closing the briefing map. Some parameters can be adjusted mid-mission, while some can't. (SEE NOTE 2)

Using In Another Mission

This system was designed to be modular, if you want to rip it out for your own use, the KISKA Parameter Menu folder is primarily what you need. There are other KISKA functions that are used inside of the framework, but I'm not going to list them all here; you can find the rest of those in the KISKA Utility Functions folder. Then just look at the Mission Params Config for how to actually set up parameters with examples.

Two more things. If you intend to have parameters set from the menu be used during initialization, you need to wait for the loading of the parameters to be completed. I accomplished this in the initServer.sqf by using the following. I also did this in the initPlayerLocal.sqf.

waitUntil {
	localNamespace getVariable ["KISKA_missionParams_preloadFinished",false]
};

Once all global variables have been loaded from any changes made in the briefing menu, the local machine will set KISKA_missionParams_preloadFinished in the localNamespace to true.

Lastly, you need to have the briefing attribute in the description.ext be set to on:

// inside description.ext
briefing = 1;

Notes:

1. Only admins or hosts can commit changes. It is worth noting that this panel is NOT currently updated remotely (e.g. if 2 admins have the panel open simultaneously and one commits changes, the other admin's panel will NOT show those changes until they refresh (reopen) a category or the entire menu).
2. Hover the mouse cursor over the "title" of the parameter to get some info about it. One of these is whether or not the parameter "Requires [a] Restart" of the mission.