How to export list of VST effects and instruments?

The Plugins.xml file might be a better place to start, but there are a bunch of XML files that are not documented, so feel free to experiment!

Select-Xml -Path .\Plugins.xml -XPath  "//plugin[@name]" | ForEach-Object {$_.Node.vendor + "," + $_.Node.name }

I don’t know where the information is stored as to the VST3/2-ness of a plugin, but the items seem to have a “object ID” which appears to be unique.