When adding

[UdonBehaviourSyncMode(BehaviourSyncMode.NoVariableSync)]

to an udon# class, It will just continue using the last setting.

For example if you add

[UdonBehaviourSyncMode(BehaviourSyncMode.Continuous)]

and then compile, then change it to

[UdonBehaviourSyncMode(BehaviourSyncMode.NoVariableSync)]

and compile again, you get the expected behavior, and calling SendCustomNetworkEvent() works.

If you then change it to

[UdonBehaviourSyncMode(BehaviourSyncMode.None)]

and compile, then change it to

[UdonBehaviourSyncMode(BehaviourSyncMode.NoVariableSync)]

and compile again It will continue to behave exactly as if it's still set to None. SendCustomNetworkEvent() does not work.

This is on an object that doesn't have any other scripts on it. I haven't tested the case with other scripts.

You can look at the debug inspector to confirm that this is what is happening.

From the documentation:

"NoVariableSync:

Enforces that there are no synced variables on the behaviour, hides the sync mode selection dropdown, and allows you to use the behaviours on GameObjects that use either Manual or Continuous sync."

It seems like the case where a script using NoVariableSync being used on an object that doesn't have another script on it may have been overlooked.

Since I'm updating a script in a prefab I'm releasing from None to NoVariableSync because I want to use network events now, it's not going to work for anyone updating to the new version. I am forced to set it to Continuous. Does anyone know if it makes any difference to bandwidth usage?