@smashclash,

We currently do not have a designated remote trigger, however this is something that our teams have been exploring and looking to add - even if it isn't in a switch form, but more like Tapos S200B. While it may still be a bit of a wait for a device to release, you can always install another switch and use Smart Actions to turn on both lights if you want them to turn on and off whenever one is changed.

  @smashclash,

In general smart actions run on the cloud, so I have a feeling that the dimming functionality may be too delayed to provide a smooth experience. We are beginning to see functionality such as what you mentioned being considered. However, it is only just in the initial phases of testing and is more related to a button interactions rather than another switch. I believe that there are already large updates planned for the coming months so we may learn more about how/if the feature can be added soon.

The functionality does somewhat exist for controlling a smart light bulb, as there are brightness commands, but without the triggers for the dimmers, it is not possible.

You can use the set lighting function to have a light set to a specific level, but you are correct; you cannot create an action that will dim both lights at the same time based on dimming one of the switches; for this, you would need to create a group in the app and dim the group from there.