No, im sorry, Better Logic only has one Trigger/When card for when a Variable changed.
So, if you would be able to create it there, there is absolutly no way the app/i can know what kind of variable you want to make.
I am thinking about adding extra When cards for Trigger/Text/Number/Boolean, but i am not sure.
When i was thinking about adding a camera variable, i realized:
The more i am updating BL and working more intens with it, the more i realize that, afaik right now, everything that can be done with Better Logic, can be done with the Advanced Virtual Devices from Device Capabilities.
You can add yes-no/text/number/trigger/button/lists/camera fields and put Create Tags on.
Now you have the exact same thing as BL has, except the tags are grouped in a device instead of the app.
So i am not sure which way i will go with BL. But i did want to add the in-flow-cariables-creation where it was possbible: every flowcard which is for a specific variable type.
