I don’t see a problem with it. Though I don’t think you can keep it formatted as JSON like it is in your example. You will need to follow the format for metadata.
I use Item metadata for a number of situations and even wrote a design pattern about it. My [Scripted Automation] Multi-day Time of Day Library example uses complex metadata, though not as complex as you will need.
Not so much I find. Simple metadata is pretty readable but something as complex as the above will become a little hard to follow I think. But YMMV.
The following is explained at Metadata — openHAB Helper Libraries documentation
But to quote the DP above, Metadata has three main parts.
- Namespace: the root category, can contain multiple Values
- Value: Single value for the namespace
- Key/value pairs: an array of keys and their values
In your example above, “alexa” is the namespace, “Fan” is a value and [ type="oscellating", speedSteps=3 ] is the Key/value array.
If you want to access the type value you need to call
get_key_value("testGU10L", "alexa", "type")
You’ve already shown how to get the value “Fan”.