MQTT Json/Template - need ON command to also include brightness

Hi,
Have 12v lights controlled by Wemos D1 mini in my garden and I have a problem, currently I’m using default MQTT with command and brightness channels and it works fine as current state is stored in MQTT both for state and brightness.

Now I like to add Transitions and that is not supported by the default MQTT so I’m must change to Json or Template but I can not get it to work as Brightness is not sent in every message and if Wemos has been down and restarts it can not get the brigthness level as it may not have been sent in last message and when I click on in GUI only on is sent not Brightness as I would like.

Anyone have any solution for this?

Thanks Mats