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MSFS Multi-player support in MSFS - A: vars, L: vars and Z:vars

I suspect the support for multiplayer in aircraft design is going to see a bit of work/clarification/development in the coming months.

L: vars are freely named unitless custom variables that can be used in XML RPN and html/js gauges, e.g. XML: 42 (>L:PYLON_ANIM), JS: SimVar.SetSimVarValue("L:PYLON_ANIM","number",42);. These vars are also supported in the "LocalVar" sound.xml entries. Also they can be viewed live for debug purposes in the Behaviours window of the SDK.

Z: vars are very similar to A: vars in terms of functionality, and L: vars in terms of access, can be shared XML-JS, but must have names that don't clash with existing MSFS variables. e.g. 42 (>Z:UNIQ_NEW_VAR) They cannot be viewed live in the SDK tools, and are not shared between planes locally in multiplayer (see below).

A: vars are the vars that are updated by the core sim & have existed forever and evolved from FSX into MSFS, like Z: vars they apply to the user aircraft or the currently relevant environment.

Re multiplayer, currently:

L: vars are (bizarrely, to me) shared between YOUR aircraft and every other matching AI aircraft in YOUR sim (I know how it's implemented, just seems an odd design choice). So if you use an L: var to move an animation or enable the visibility of an effect, that effect/animation will appear on every aircraft of the same type currently visible in YOUR sim (i.e. typically multiplayer planes with matching AI models in your sim). None of these vars are communicated in multiplayer across the internet to affect any planes in other users sims, most notably the AI version of YOUR aircraft flying in other users sims will not be influenced by these L: vars.

Z: vars are entirely local to YOUR aircraft in YOUR sim, so affect no other planes in your sim or the AI version of your plane in other multiplayer sims.

A: vars - here is the mystery, and the main reason for this post. The SDK docs have just been updated to remove any reference to "Shared Cockpit" / "All Aircraft" which used to provide an inaccurate clue whether they were shared over multiplayer. As of yesterday (A:RUDDER DEFLECTION PCT, percent) definitely works but AFAIK (A:GEAR HANDLE POSITION, "number") is not working to move the gear, and I notice the Asobo Gear template is using (A:GEAR ANIMATION POSITION, percent) which was NOT listed in the docs as "All Aircraft" but the GEAR HANDLE POSITION was (and the Asobo Airbus definitely communicates it's gear position successfully).

There's plenty of hearsay/heuristics of what might work/not work in multiplayer (e.g. all external lights) but this isn't reliable and the crucial vars are the ones that allow you to send more than a boolean.

Anyone know of a decent source of which A: vars to rely on in multiplayer?