It is standard behaviour.
In my copy of Picard I haven’t gone into too many of the plugins. Didn’t really want to overload the tags in my files, and most of the plugins are very sparsely described in the manual.
The only plugins I have ticked are “Add cluster as release”, “Copy cluster to clipboard” and “Release type”.
I added “Release type” as I wanted to know if it was EP, Single, etc.
So nothing special done in Picard to bring in the excess of data available.
I don’t have too much classical music. Yet some of the bands I am into seem to have a huge depth of data added to a release. A random example would be Pink Floyd:
Look at track 7 - like many on here it is FLOODED with all kinds of extra data on everything from the lead sax to the tea boy. And all of that is going over to my files thanks to Picard.
-=-=- This next paragraph is going OT… any MOD who can slice this bit off below this line and make it the start of a new post? -=-=-
I should note that there are a big heap of plugins that are beyond confusing to me. Things like “Classical Extras” are among those that confuse me. The help files are too basic. Not going beyond a sentence or two to say what the plugin does. So I have generally shied away from adding too many of these.