The “output” attribute has never been necessary for me to use, but I didn’t understand it very well, there is not much information in the documentation.
I saw that you can (supposedly) use the values “toHtml, toStaticHtml, toText, toJson” which when put into practice does not allow another value other than “1”.
Looking at the file vendor/magento/framework/View/Layout/etc/elements.xsd notice that “elementOutputType” is locked to only that value, as a test add the previous ones mentioned and it already allows me to use them but without any results.
My question is, was output used previously and is already obsolete or why is it blocked by default at “1” and not the rest of the options that I find on the internet?
<xs:simpleType name="elementOutputType">
<xs:restriction base="xs:string">
<xs:enumeration value="1"/>
</xs:restriction>
</xs:simpleType>